linux/arch/powerpc/kvm/book3s_xics.c

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/*
* Copyright 2012 Michael Ellerman, IBM Corporation.
* Copyright 2012 Benjamin Herrenschmidt, IBM Corporation.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License, version 2, as
* published by the Free Software Foundation.
*/
#include <linux/kernel.h>
#include <linux/kvm_host.h>
#include <linux/err.h>
#include <linux/gfp.h>
#include <linux/anon_inodes.h>
#include <linux/spinlock.h>
#include <linux/uaccess.h>
#include <asm/kvm_book3s.h>
#include <asm/kvm_ppc.h>
#include <asm/hvcall.h>
#include <asm/xics.h>
#include <asm/debugfs.h>
#include <asm/time.h>
#include <linux/seq_file.h>
#include "book3s_xics.h"
#if 1
#define XICS_DBG(fmt...) do { } while (0)
#else
#define XICS_DBG(fmt...) trace_printk(fmt)
#endif
#define ENABLE_REALMODE true
#define DEBUG_REALMODE false
/*
* LOCKING
* =======
*
* Each ICS has a spin lock protecting the information about the IRQ
* sources and avoiding simultaneous deliveries of the same interrupt.
*
* ICP operations are done via a single compare & swap transaction
* (most ICP state fits in the union kvmppc_icp_state)
*/
/*
* TODO
* ====
*
* - To speed up resends, keep a bitmap of "resend" set bits in the
* ICS
*
* - Speed up server# -> ICP lookup (array ? hash table ?)
*
* - Make ICS lockless as well, or at least a per-interrupt lock or hashed
* locks array to improve scalability
*/
/* -- ICS routines -- */
static void icp_deliver_irq(struct kvmppc_xics *xics, struct kvmppc_icp *icp,
u32 new_irq, bool check_resend);
/*
* Return value ideally indicates how the interrupt was handled, but no
* callers look at it (given that we don't implement KVM_IRQ_LINE_STATUS),
* so just return 0.
*/
static int ics_deliver_irq(struct kvmppc_xics *xics, u32 irq, u32 level)
{
struct ics_irq_state *state;
struct kvmppc_ics *ics;
u16 src;
u32 pq_old, pq_new;
XICS_DBG("ics deliver %#x (level: %d)\n", irq, level);
ics = kvmppc_xics_find_ics(xics, irq, &src);
if (!ics) {
XICS_DBG("ics_deliver_irq: IRQ 0x%06x not found !\n", irq);
return -EINVAL;
}
state = &ics->irq_state[src];
if (!state->exists)
return -EINVAL;
if (level == KVM_INTERRUPT_SET_LEVEL || level == KVM_INTERRUPT_SET)
level = 1;
else if (level == KVM_INTERRUPT_UNSET)
level = 0;
/*
* Take other values the same as 1, consistent with original code.
* maybe WARN here?
*/
if (!state->lsi && level == 0) /* noop for MSI */
return 0;
do {
pq_old = state->pq_state;
if (state->lsi) {
if (level) {
if (pq_old & PQ_PRESENTED)
/* Setting already set LSI ... */
return 0;
pq_new = PQ_PRESENTED;
} else
pq_new = 0;
} else
pq_new = ((pq_old << 1) & 3) | PQ_PRESENTED;
} while (cmpxchg(&state->pq_state, pq_old, pq_new) != pq_old);
/* Test P=1, Q=0, this is the only case where we present */
if (pq_new == PQ_PRESENTED)
icp_deliver_irq(xics, NULL, irq, false);
KVM: PPC: Book3S HV: Set server for passed-through interrupts When a guest has a PCI pass-through device with an interrupt, it will direct the interrupt to a particular guest VCPU. In fact the physical interrupt might arrive on any CPU, and then get delivered to the target VCPU in the emulated XICS (guest interrupt controller), and eventually delivered to the target VCPU. Now that we have code to handle device interrupts in real mode without exiting to the host kernel, there is an advantage to having the device interrupt arrive on the same sub(core) as the target VCPU is running on. In this situation, the interrupt can be delivered to the target VCPU without any exit to the host kernel (using a hypervisor doorbell interrupt between threads if necessary). This patch aims to get passed-through device interrupts arriving on the correct core by setting the interrupt server in the real hardware XICS for the interrupt to the first thread in the (sub)core where its target VCPU is running. We do this in the real-mode H_EOI code because the H_EOI handler already needs to look at the emulated ICS state for the interrupt (whereas the H_XIRR handler doesn't), and we know we are running in the target VCPU context at that point. We set the server CPU in hardware using an OPAL call, regardless of what the IRQ affinity mask for the interrupt says, and without updating the affinity mask. This amounts to saying that when an interrupt is passed through to a guest, as a matter of policy we allow the guest's affinity for the interrupt to override the host's. This is inspired by an earlier patch from Suresh Warrier, although none of this code came from that earlier patch. Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2016-08-19 13:35:56 +08:00
/* Record which CPU this arrived on for passed-through interrupts */
if (state->host_irq)
state->intr_cpu = raw_smp_processor_id();
return 0;
}
static void ics_check_resend(struct kvmppc_xics *xics, struct kvmppc_ics *ics,
struct kvmppc_icp *icp)
{
int i;
for (i = 0; i < KVMPPC_XICS_IRQ_PER_ICS; i++) {
struct ics_irq_state *state = &ics->irq_state[i];
if (state->resend) {
XICS_DBG("resend %#x prio %#x\n", state->number,
state->priority);
icp_deliver_irq(xics, icp, state->number, true);
}
}
}
static bool write_xive(struct kvmppc_xics *xics, struct kvmppc_ics *ics,
struct ics_irq_state *state,
u32 server, u32 priority, u32 saved_priority)
{
bool deliver;
unsigned long flags;
local_irq_save(flags);
arch_spin_lock(&ics->lock);
state->server = server;
state->priority = priority;
state->saved_priority = saved_priority;
deliver = false;
if ((state->masked_pending || state->resend) && priority != MASKED) {
state->masked_pending = 0;
state->resend = 0;
deliver = true;
}
arch_spin_unlock(&ics->lock);
local_irq_restore(flags);
return deliver;
}
int kvmppc_xics_set_xive(struct kvm *kvm, u32 irq, u32 server, u32 priority)
{
struct kvmppc_xics *xics = kvm->arch.xics;
struct kvmppc_icp *icp;
struct kvmppc_ics *ics;
struct ics_irq_state *state;
u16 src;
if (!xics)
return -ENODEV;
ics = kvmppc_xics_find_ics(xics, irq, &src);
if (!ics)
return -EINVAL;
state = &ics->irq_state[src];
icp = kvmppc_xics_find_server(kvm, server);
if (!icp)
return -EINVAL;
XICS_DBG("set_xive %#x server %#x prio %#x MP:%d RS:%d\n",
irq, server, priority,
state->masked_pending, state->resend);
if (write_xive(xics, ics, state, server, priority, priority))
icp_deliver_irq(xics, icp, irq, false);
return 0;
}
int kvmppc_xics_get_xive(struct kvm *kvm, u32 irq, u32 *server, u32 *priority)
{
struct kvmppc_xics *xics = kvm->arch.xics;
struct kvmppc_ics *ics;
struct ics_irq_state *state;
u16 src;
unsigned long flags;
if (!xics)
return -ENODEV;
ics = kvmppc_xics_find_ics(xics, irq, &src);
if (!ics)
return -EINVAL;
state = &ics->irq_state[src];
local_irq_save(flags);
arch_spin_lock(&ics->lock);
*server = state->server;
*priority = state->priority;
arch_spin_unlock(&ics->lock);
local_irq_restore(flags);
return 0;
}
int kvmppc_xics_int_on(struct kvm *kvm, u32 irq)
{
struct kvmppc_xics *xics = kvm->arch.xics;
struct kvmppc_icp *icp;
struct kvmppc_ics *ics;
struct ics_irq_state *state;
u16 src;
if (!xics)
return -ENODEV;
ics = kvmppc_xics_find_ics(xics, irq, &src);
if (!ics)
return -EINVAL;
state = &ics->irq_state[src];
icp = kvmppc_xics_find_server(kvm, state->server);
if (!icp)
return -EINVAL;
if (write_xive(xics, ics, state, state->server, state->saved_priority,
state->saved_priority))
icp_deliver_irq(xics, icp, irq, false);
return 0;
}
int kvmppc_xics_int_off(struct kvm *kvm, u32 irq)
{
struct kvmppc_xics *xics = kvm->arch.xics;
struct kvmppc_ics *ics;
struct ics_irq_state *state;
u16 src;
if (!xics)
return -ENODEV;
ics = kvmppc_xics_find_ics(xics, irq, &src);
if (!ics)
return -EINVAL;
state = &ics->irq_state[src];
write_xive(xics, ics, state, state->server, MASKED, state->priority);
return 0;
}
/* -- ICP routines, including hcalls -- */
static inline bool icp_try_update(struct kvmppc_icp *icp,
union kvmppc_icp_state old,
union kvmppc_icp_state new,
bool change_self)
{
bool success;
/* Calculate new output value */
new.out_ee = (new.xisr && (new.pending_pri < new.cppr));
/* Attempt atomic update */
success = cmpxchg64(&icp->state.raw, old.raw, new.raw) == old.raw;
if (!success)
goto bail;
XICS_DBG("UPD [%04lx] - C:%02x M:%02x PP: %02x PI:%06x R:%d O:%d\n",
icp->server_num,
old.cppr, old.mfrr, old.pending_pri, old.xisr,
old.need_resend, old.out_ee);
XICS_DBG("UPD - C:%02x M:%02x PP: %02x PI:%06x R:%d O:%d\n",
new.cppr, new.mfrr, new.pending_pri, new.xisr,
new.need_resend, new.out_ee);
/*
* Check for output state update
*
* Note that this is racy since another processor could be updating
* the state already. This is why we never clear the interrupt output
* here, we only ever set it. The clear only happens prior to doing
* an update and only by the processor itself. Currently we do it
* in Accept (H_XIRR) and Up_Cppr (H_XPPR).
*
* We also do not try to figure out whether the EE state has changed,
* we unconditionally set it if the new state calls for it. The reason
* for that is that we opportunistically remove the pending interrupt
* flag when raising CPPR, so we need to set it back here if an
* interrupt is still pending.
*/
if (new.out_ee) {
kvmppc_book3s_queue_irqprio(icp->vcpu,
BOOK3S_INTERRUPT_EXTERNAL);
if (!change_self)
kvmppc_fast_vcpu_kick(icp->vcpu);
}
bail:
return success;
}
static void icp_check_resend(struct kvmppc_xics *xics,
struct kvmppc_icp *icp)
{
u32 icsid;
/* Order this load with the test for need_resend in the caller */
smp_rmb();
for_each_set_bit(icsid, icp->resend_map, xics->max_icsid + 1) {
struct kvmppc_ics *ics = xics->ics[icsid];
if (!test_and_clear_bit(icsid, icp->resend_map))
continue;
if (!ics)
continue;
ics_check_resend(xics, ics, icp);
}
}
static bool icp_try_to_deliver(struct kvmppc_icp *icp, u32 irq, u8 priority,
u32 *reject)
{
union kvmppc_icp_state old_state, new_state;
bool success;
XICS_DBG("try deliver %#x(P:%#x) to server %#lx\n", irq, priority,
icp->server_num);
do {
old_state = new_state = READ_ONCE(icp->state);
*reject = 0;
/* See if we can deliver */
success = new_state.cppr > priority &&
new_state.mfrr > priority &&
new_state.pending_pri > priority;
/*
* If we can, check for a rejection and perform the
* delivery
*/
if (success) {
*reject = new_state.xisr;
new_state.xisr = irq;
new_state.pending_pri = priority;
} else {
/*
* If we failed to deliver we set need_resend
* so a subsequent CPPR state change causes us
* to try a new delivery.
*/
new_state.need_resend = true;
}
} while (!icp_try_update(icp, old_state, new_state, false));
return success;
}
static void icp_deliver_irq(struct kvmppc_xics *xics, struct kvmppc_icp *icp,
u32 new_irq, bool check_resend)
{
struct ics_irq_state *state;
struct kvmppc_ics *ics;
u32 reject;
u16 src;
unsigned long flags;
/*
* This is used both for initial delivery of an interrupt and
* for subsequent rejection.
*
* Rejection can be racy vs. resends. We have evaluated the
* rejection in an atomic ICP transaction which is now complete,
* so potentially the ICP can already accept the interrupt again.
*
* So we need to retry the delivery. Essentially the reject path
* boils down to a failed delivery. Always.
*
* Now the interrupt could also have moved to a different target,
* thus we may need to re-do the ICP lookup as well
*/
again:
/* Get the ICS state and lock it */
ics = kvmppc_xics_find_ics(xics, new_irq, &src);
if (!ics) {
XICS_DBG("icp_deliver_irq: IRQ 0x%06x not found !\n", new_irq);
return;
}
state = &ics->irq_state[src];
/* Get a lock on the ICS */
local_irq_save(flags);
arch_spin_lock(&ics->lock);
/* Get our server */
if (!icp || state->server != icp->server_num) {
icp = kvmppc_xics_find_server(xics->kvm, state->server);
if (!icp) {
pr_warn("icp_deliver_irq: IRQ 0x%06x server 0x%x not found !\n",
new_irq, state->server);
goto out;
}
}
if (check_resend)
if (!state->resend)
goto out;
/* Clear the resend bit of that interrupt */
state->resend = 0;
/*
* If masked, bail out
*
* Note: PAPR doesn't mention anything about masked pending
* when doing a resend, only when doing a delivery.
*
* However that would have the effect of losing a masked
* interrupt that was rejected and isn't consistent with
* the whole masked_pending business which is about not
* losing interrupts that occur while masked.
*
* I don't differentiate normal deliveries and resends, this
* implementation will differ from PAPR and not lose such
* interrupts.
*/
if (state->priority == MASKED) {
XICS_DBG("irq %#x masked pending\n", new_irq);
state->masked_pending = 1;
goto out;
}
/*
* Try the delivery, this will set the need_resend flag
* in the ICP as part of the atomic transaction if the
* delivery is not possible.
*
* Note that if successful, the new delivery might have itself
* rejected an interrupt that was "delivered" before we took the
* ics spin lock.
*
* In this case we do the whole sequence all over again for the
* new guy. We cannot assume that the rejected interrupt is less
* favored than the new one, and thus doesn't need to be delivered,
* because by the time we exit icp_try_to_deliver() the target
* processor may well have alrady consumed & completed it, and thus
* the rejected interrupt might actually be already acceptable.
*/
if (icp_try_to_deliver(icp, new_irq, state->priority, &reject)) {
/*
* Delivery was successful, did we reject somebody else ?
*/
if (reject && reject != XICS_IPI) {
arch_spin_unlock(&ics->lock);
local_irq_restore(flags);
new_irq = reject;
check_resend = 0;
goto again;
}
} else {
/*
* We failed to deliver the interrupt we need to set the
* resend map bit and mark the ICS state as needing a resend
*/
state->resend = 1;
/*
* Make sure when checking resend, we don't miss the resend
* if resend_map bit is seen and cleared.
*/
smp_wmb();
set_bit(ics->icsid, icp->resend_map);
/*
* If the need_resend flag got cleared in the ICP some time
* between icp_try_to_deliver() atomic update and now, then
* we know it might have missed the resend_map bit. So we
* retry
*/
smp_mb();
if (!icp->state.need_resend) {
state->resend = 0;
arch_spin_unlock(&ics->lock);
local_irq_restore(flags);
check_resend = 0;
goto again;
}
}
out:
arch_spin_unlock(&ics->lock);
local_irq_restore(flags);
}
static void icp_down_cppr(struct kvmppc_xics *xics, struct kvmppc_icp *icp,
u8 new_cppr)
{
union kvmppc_icp_state old_state, new_state;
bool resend;
/*
* This handles several related states in one operation:
*
* ICP State: Down_CPPR
*
* Load CPPR with new value and if the XISR is 0
* then check for resends:
*
* ICP State: Resend
*
* If MFRR is more favored than CPPR, check for IPIs
* and notify ICS of a potential resend. This is done
* asynchronously (when used in real mode, we will have
* to exit here).
*
* We do not handle the complete Check_IPI as documented
* here. In the PAPR, this state will be used for both
* Set_MFRR and Down_CPPR. However, we know that we aren't
* changing the MFRR state here so we don't need to handle
* the case of an MFRR causing a reject of a pending irq,
* this will have been handled when the MFRR was set in the
* first place.
*
* Thus we don't have to handle rejects, only resends.
*
* When implementing real mode for HV KVM, resend will lead to
* a H_TOO_HARD return and the whole transaction will be handled
* in virtual mode.
*/
do {
old_state = new_state = READ_ONCE(icp->state);
/* Down_CPPR */
new_state.cppr = new_cppr;
/*
* Cut down Resend / Check_IPI / IPI
*
* The logic is that we cannot have a pending interrupt
* trumped by an IPI at this point (see above), so we
* know that either the pending interrupt is already an
* IPI (in which case we don't care to override it) or
* it's either more favored than us or non existent
*/
if (new_state.mfrr < new_cppr &&
new_state.mfrr <= new_state.pending_pri) {
WARN_ON(new_state.xisr != XICS_IPI &&
new_state.xisr != 0);
new_state.pending_pri = new_state.mfrr;
new_state.xisr = XICS_IPI;
}
/* Latch/clear resend bit */
resend = new_state.need_resend;
new_state.need_resend = 0;
} while (!icp_try_update(icp, old_state, new_state, true));
/*
* Now handle resend checks. Those are asynchronous to the ICP
* state update in HW (ie bus transactions) so we can handle them
* separately here too
*/
if (resend)
icp_check_resend(xics, icp);
}
static noinline unsigned long kvmppc_h_xirr(struct kvm_vcpu *vcpu)
{
union kvmppc_icp_state old_state, new_state;
struct kvmppc_icp *icp = vcpu->arch.icp;
u32 xirr;
/* First, remove EE from the processor */
kvmppc_book3s_dequeue_irqprio(icp->vcpu, BOOK3S_INTERRUPT_EXTERNAL);
/*
* ICP State: Accept_Interrupt
*
* Return the pending interrupt (if any) along with the
* current CPPR, then clear the XISR & set CPPR to the
* pending priority
*/
do {
old_state = new_state = READ_ONCE(icp->state);
xirr = old_state.xisr | (((u32)old_state.cppr) << 24);
if (!old_state.xisr)
break;
new_state.cppr = new_state.pending_pri;
new_state.pending_pri = 0xff;
new_state.xisr = 0;
} while (!icp_try_update(icp, old_state, new_state, true));
XICS_DBG("h_xirr vcpu %d xirr %#x\n", vcpu->vcpu_id, xirr);
return xirr;
}
static noinline int kvmppc_h_ipi(struct kvm_vcpu *vcpu, unsigned long server,
unsigned long mfrr)
{
union kvmppc_icp_state old_state, new_state;
struct kvmppc_xics *xics = vcpu->kvm->arch.xics;
struct kvmppc_icp *icp;
u32 reject;
bool resend;
bool local;
XICS_DBG("h_ipi vcpu %d to server %lu mfrr %#lx\n",
vcpu->vcpu_id, server, mfrr);
icp = vcpu->arch.icp;
local = icp->server_num == server;
if (!local) {
icp = kvmppc_xics_find_server(vcpu->kvm, server);
if (!icp)
return H_PARAMETER;
}
/*
* ICP state: Set_MFRR
*
* If the CPPR is more favored than the new MFRR, then
* nothing needs to be rejected as there can be no XISR to
* reject. If the MFRR is being made less favored then
* there might be a previously-rejected interrupt needing
* to be resent.
*
KVM: PPC: Book3S HV: Fix inaccuracies in ICP emulation for H_IPI This fixes some inaccuracies in the state machine for the virtualized ICP when implementing the H_IPI hcall (Set_MFFR and related states): 1. The old code wipes out any pending interrupts when the new MFRR is more favored than the CPPR but less favored than a pending interrupt (by always modifying xisr and the pending_pri). This can cause us to lose a pending external interrupt. The correct code here is to only modify the pending_pri and xisr in the ICP if the MFRR is equal to or more favored than the current pending pri (since in this case, it is guaranteed that that there cannot be a pending external interrupt). The code changes are required in both kvmppc_rm_h_ipi and kvmppc_h_ipi. 2. Again, in both kvmppc_rm_h_ipi and kvmppc_h_ipi, there is a check for whether MFRR is being made less favored AND further if new MFFR is also less favored than the current CPPR, we check for any resends pending in the ICP. These checks look like they are designed to cover the case where if the MFRR is being made less favored, we opportunistically trigger a resend of any interrupts that had been previously rejected. Although, this is not a state described by PAPR, this is an action we actually need to do especially if the CPPR is already at 0xFF. Because in this case, the resend bit will stay on until another ICP state change which may be a long time coming and the interrupt stays pending until then. The current code which checks for MFRR < CPPR is broken when CPPR is 0xFF since it will not get triggered in that case. Ideally, we would want to do a resend only if prio(pending_interrupt) < mfrr && prio(pending_interrupt) < cppr where pending interrupt is the one that was rejected. But we don't have the priority of the pending interrupt state saved, so we simply trigger a resend whenever the MFRR is made less favored. 3. In kvmppc_rm_h_ipi, where we save state to pass resends to the virtual mode, we also need to save the ICP whose need_resend we reset since this does not need to be my ICP (vcpu->arch.icp) as is incorrectly assumed by the current code. A new field rm_resend_icp is added to the kvmppc_icp structure for this purpose. Signed-off-by: Suresh Warrier <warrier@linux.vnet.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-11-03 12:51:59 +08:00
* ICP state: Check_IPI
*
* If the CPPR is less favored, then we might be replacing
KVM: PPC: Book3S HV: Fix inaccuracies in ICP emulation for H_IPI This fixes some inaccuracies in the state machine for the virtualized ICP when implementing the H_IPI hcall (Set_MFFR and related states): 1. The old code wipes out any pending interrupts when the new MFRR is more favored than the CPPR but less favored than a pending interrupt (by always modifying xisr and the pending_pri). This can cause us to lose a pending external interrupt. The correct code here is to only modify the pending_pri and xisr in the ICP if the MFRR is equal to or more favored than the current pending pri (since in this case, it is guaranteed that that there cannot be a pending external interrupt). The code changes are required in both kvmppc_rm_h_ipi and kvmppc_h_ipi. 2. Again, in both kvmppc_rm_h_ipi and kvmppc_h_ipi, there is a check for whether MFRR is being made less favored AND further if new MFFR is also less favored than the current CPPR, we check for any resends pending in the ICP. These checks look like they are designed to cover the case where if the MFRR is being made less favored, we opportunistically trigger a resend of any interrupts that had been previously rejected. Although, this is not a state described by PAPR, this is an action we actually need to do especially if the CPPR is already at 0xFF. Because in this case, the resend bit will stay on until another ICP state change which may be a long time coming and the interrupt stays pending until then. The current code which checks for MFRR < CPPR is broken when CPPR is 0xFF since it will not get triggered in that case. Ideally, we would want to do a resend only if prio(pending_interrupt) < mfrr && prio(pending_interrupt) < cppr where pending interrupt is the one that was rejected. But we don't have the priority of the pending interrupt state saved, so we simply trigger a resend whenever the MFRR is made less favored. 3. In kvmppc_rm_h_ipi, where we save state to pass resends to the virtual mode, we also need to save the ICP whose need_resend we reset since this does not need to be my ICP (vcpu->arch.icp) as is incorrectly assumed by the current code. A new field rm_resend_icp is added to the kvmppc_icp structure for this purpose. Signed-off-by: Suresh Warrier <warrier@linux.vnet.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-11-03 12:51:59 +08:00
* an interrupt, and thus need to possibly reject it.
*
KVM: PPC: Book3S HV: Fix inaccuracies in ICP emulation for H_IPI This fixes some inaccuracies in the state machine for the virtualized ICP when implementing the H_IPI hcall (Set_MFFR and related states): 1. The old code wipes out any pending interrupts when the new MFRR is more favored than the CPPR but less favored than a pending interrupt (by always modifying xisr and the pending_pri). This can cause us to lose a pending external interrupt. The correct code here is to only modify the pending_pri and xisr in the ICP if the MFRR is equal to or more favored than the current pending pri (since in this case, it is guaranteed that that there cannot be a pending external interrupt). The code changes are required in both kvmppc_rm_h_ipi and kvmppc_h_ipi. 2. Again, in both kvmppc_rm_h_ipi and kvmppc_h_ipi, there is a check for whether MFRR is being made less favored AND further if new MFFR is also less favored than the current CPPR, we check for any resends pending in the ICP. These checks look like they are designed to cover the case where if the MFRR is being made less favored, we opportunistically trigger a resend of any interrupts that had been previously rejected. Although, this is not a state described by PAPR, this is an action we actually need to do especially if the CPPR is already at 0xFF. Because in this case, the resend bit will stay on until another ICP state change which may be a long time coming and the interrupt stays pending until then. The current code which checks for MFRR < CPPR is broken when CPPR is 0xFF since it will not get triggered in that case. Ideally, we would want to do a resend only if prio(pending_interrupt) < mfrr && prio(pending_interrupt) < cppr where pending interrupt is the one that was rejected. But we don't have the priority of the pending interrupt state saved, so we simply trigger a resend whenever the MFRR is made less favored. 3. In kvmppc_rm_h_ipi, where we save state to pass resends to the virtual mode, we also need to save the ICP whose need_resend we reset since this does not need to be my ICP (vcpu->arch.icp) as is incorrectly assumed by the current code. A new field rm_resend_icp is added to the kvmppc_icp structure for this purpose. Signed-off-by: Suresh Warrier <warrier@linux.vnet.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-11-03 12:51:59 +08:00
* ICP State: IPI
*
* Besides rejecting any pending interrupts, we also
* update XISR and pending_pri to mark IPI as pending.
*
* PAPR does not describe this state, but if the MFRR is being
* made less favored than its earlier value, there might be
* a previously-rejected interrupt needing to be resent.
* Ideally, we would want to resend only if
* prio(pending_interrupt) < mfrr &&
* prio(pending_interrupt) < cppr
* where pending interrupt is the one that was rejected. But
* we don't have that state, so we simply trigger a resend
* whenever the MFRR is made less favored.
*/
do {
old_state = new_state = READ_ONCE(icp->state);
/* Set_MFRR */
new_state.mfrr = mfrr;
/* Check_IPI */
reject = 0;
resend = false;
if (mfrr < new_state.cppr) {
/* Reject a pending interrupt if not an IPI */
KVM: PPC: Book3S HV: Fix inaccuracies in ICP emulation for H_IPI This fixes some inaccuracies in the state machine for the virtualized ICP when implementing the H_IPI hcall (Set_MFFR and related states): 1. The old code wipes out any pending interrupts when the new MFRR is more favored than the CPPR but less favored than a pending interrupt (by always modifying xisr and the pending_pri). This can cause us to lose a pending external interrupt. The correct code here is to only modify the pending_pri and xisr in the ICP if the MFRR is equal to or more favored than the current pending pri (since in this case, it is guaranteed that that there cannot be a pending external interrupt). The code changes are required in both kvmppc_rm_h_ipi and kvmppc_h_ipi. 2. Again, in both kvmppc_rm_h_ipi and kvmppc_h_ipi, there is a check for whether MFRR is being made less favored AND further if new MFFR is also less favored than the current CPPR, we check for any resends pending in the ICP. These checks look like they are designed to cover the case where if the MFRR is being made less favored, we opportunistically trigger a resend of any interrupts that had been previously rejected. Although, this is not a state described by PAPR, this is an action we actually need to do especially if the CPPR is already at 0xFF. Because in this case, the resend bit will stay on until another ICP state change which may be a long time coming and the interrupt stays pending until then. The current code which checks for MFRR < CPPR is broken when CPPR is 0xFF since it will not get triggered in that case. Ideally, we would want to do a resend only if prio(pending_interrupt) < mfrr && prio(pending_interrupt) < cppr where pending interrupt is the one that was rejected. But we don't have the priority of the pending interrupt state saved, so we simply trigger a resend whenever the MFRR is made less favored. 3. In kvmppc_rm_h_ipi, where we save state to pass resends to the virtual mode, we also need to save the ICP whose need_resend we reset since this does not need to be my ICP (vcpu->arch.icp) as is incorrectly assumed by the current code. A new field rm_resend_icp is added to the kvmppc_icp structure for this purpose. Signed-off-by: Suresh Warrier <warrier@linux.vnet.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-11-03 12:51:59 +08:00
if (mfrr <= new_state.pending_pri) {
reject = new_state.xisr;
KVM: PPC: Book3S HV: Fix inaccuracies in ICP emulation for H_IPI This fixes some inaccuracies in the state machine for the virtualized ICP when implementing the H_IPI hcall (Set_MFFR and related states): 1. The old code wipes out any pending interrupts when the new MFRR is more favored than the CPPR but less favored than a pending interrupt (by always modifying xisr and the pending_pri). This can cause us to lose a pending external interrupt. The correct code here is to only modify the pending_pri and xisr in the ICP if the MFRR is equal to or more favored than the current pending pri (since in this case, it is guaranteed that that there cannot be a pending external interrupt). The code changes are required in both kvmppc_rm_h_ipi and kvmppc_h_ipi. 2. Again, in both kvmppc_rm_h_ipi and kvmppc_h_ipi, there is a check for whether MFRR is being made less favored AND further if new MFFR is also less favored than the current CPPR, we check for any resends pending in the ICP. These checks look like they are designed to cover the case where if the MFRR is being made less favored, we opportunistically trigger a resend of any interrupts that had been previously rejected. Although, this is not a state described by PAPR, this is an action we actually need to do especially if the CPPR is already at 0xFF. Because in this case, the resend bit will stay on until another ICP state change which may be a long time coming and the interrupt stays pending until then. The current code which checks for MFRR < CPPR is broken when CPPR is 0xFF since it will not get triggered in that case. Ideally, we would want to do a resend only if prio(pending_interrupt) < mfrr && prio(pending_interrupt) < cppr where pending interrupt is the one that was rejected. But we don't have the priority of the pending interrupt state saved, so we simply trigger a resend whenever the MFRR is made less favored. 3. In kvmppc_rm_h_ipi, where we save state to pass resends to the virtual mode, we also need to save the ICP whose need_resend we reset since this does not need to be my ICP (vcpu->arch.icp) as is incorrectly assumed by the current code. A new field rm_resend_icp is added to the kvmppc_icp structure for this purpose. Signed-off-by: Suresh Warrier <warrier@linux.vnet.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-11-03 12:51:59 +08:00
new_state.pending_pri = mfrr;
new_state.xisr = XICS_IPI;
}
}
KVM: PPC: Book3S HV: Fix inaccuracies in ICP emulation for H_IPI This fixes some inaccuracies in the state machine for the virtualized ICP when implementing the H_IPI hcall (Set_MFFR and related states): 1. The old code wipes out any pending interrupts when the new MFRR is more favored than the CPPR but less favored than a pending interrupt (by always modifying xisr and the pending_pri). This can cause us to lose a pending external interrupt. The correct code here is to only modify the pending_pri and xisr in the ICP if the MFRR is equal to or more favored than the current pending pri (since in this case, it is guaranteed that that there cannot be a pending external interrupt). The code changes are required in both kvmppc_rm_h_ipi and kvmppc_h_ipi. 2. Again, in both kvmppc_rm_h_ipi and kvmppc_h_ipi, there is a check for whether MFRR is being made less favored AND further if new MFFR is also less favored than the current CPPR, we check for any resends pending in the ICP. These checks look like they are designed to cover the case where if the MFRR is being made less favored, we opportunistically trigger a resend of any interrupts that had been previously rejected. Although, this is not a state described by PAPR, this is an action we actually need to do especially if the CPPR is already at 0xFF. Because in this case, the resend bit will stay on until another ICP state change which may be a long time coming and the interrupt stays pending until then. The current code which checks for MFRR < CPPR is broken when CPPR is 0xFF since it will not get triggered in that case. Ideally, we would want to do a resend only if prio(pending_interrupt) < mfrr && prio(pending_interrupt) < cppr where pending interrupt is the one that was rejected. But we don't have the priority of the pending interrupt state saved, so we simply trigger a resend whenever the MFRR is made less favored. 3. In kvmppc_rm_h_ipi, where we save state to pass resends to the virtual mode, we also need to save the ICP whose need_resend we reset since this does not need to be my ICP (vcpu->arch.icp) as is incorrectly assumed by the current code. A new field rm_resend_icp is added to the kvmppc_icp structure for this purpose. Signed-off-by: Suresh Warrier <warrier@linux.vnet.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-11-03 12:51:59 +08:00
if (mfrr > old_state.mfrr) {
resend = new_state.need_resend;
new_state.need_resend = 0;
}
} while (!icp_try_update(icp, old_state, new_state, local));
/* Handle reject */
if (reject && reject != XICS_IPI)
icp_deliver_irq(xics, icp, reject, false);
/* Handle resend */
if (resend)
icp_check_resend(xics, icp);
return H_SUCCESS;
}
static int kvmppc_h_ipoll(struct kvm_vcpu *vcpu, unsigned long server)
{
union kvmppc_icp_state state;
struct kvmppc_icp *icp;
icp = vcpu->arch.icp;
if (icp->server_num != server) {
icp = kvmppc_xics_find_server(vcpu->kvm, server);
if (!icp)
return H_PARAMETER;
}
state = READ_ONCE(icp->state);
kvmppc_set_gpr(vcpu, 4, ((u32)state.cppr << 24) | state.xisr);
kvmppc_set_gpr(vcpu, 5, state.mfrr);
return H_SUCCESS;
}
static noinline void kvmppc_h_cppr(struct kvm_vcpu *vcpu, unsigned long cppr)
{
union kvmppc_icp_state old_state, new_state;
struct kvmppc_xics *xics = vcpu->kvm->arch.xics;
struct kvmppc_icp *icp = vcpu->arch.icp;
u32 reject;
XICS_DBG("h_cppr vcpu %d cppr %#lx\n", vcpu->vcpu_id, cppr);
/*
* ICP State: Set_CPPR
*
* We can safely compare the new value with the current
* value outside of the transaction as the CPPR is only
* ever changed by the processor on itself
*/
if (cppr > icp->state.cppr)
icp_down_cppr(xics, icp, cppr);
else if (cppr == icp->state.cppr)
return;
/*
* ICP State: Up_CPPR
*
* The processor is raising its priority, this can result
* in a rejection of a pending interrupt:
*
* ICP State: Reject_Current
*
* We can remove EE from the current processor, the update
* transaction will set it again if needed
*/
kvmppc_book3s_dequeue_irqprio(icp->vcpu, BOOK3S_INTERRUPT_EXTERNAL);
do {
old_state = new_state = READ_ONCE(icp->state);
reject = 0;
new_state.cppr = cppr;
if (cppr <= new_state.pending_pri) {
reject = new_state.xisr;
new_state.xisr = 0;
new_state.pending_pri = 0xff;
}
} while (!icp_try_update(icp, old_state, new_state, true));
/*
* Check for rejects. They are handled by doing a new delivery
* attempt (see comments in icp_deliver_irq).
*/
if (reject && reject != XICS_IPI)
icp_deliver_irq(xics, icp, reject, false);
}
static int ics_eoi(struct kvm_vcpu *vcpu, u32 irq)
{
struct kvmppc_xics *xics = vcpu->kvm->arch.xics;
struct kvmppc_icp *icp = vcpu->arch.icp;
struct kvmppc_ics *ics;
struct ics_irq_state *state;
u16 src;
u32 pq_old, pq_new;
/*
* ICS EOI handling: For LSI, if P bit is still set, we need to
* resend it.
*
* For MSI, we move Q bit into P (and clear Q). If it is set,
* resend it.
*/
ics = kvmppc_xics_find_ics(xics, irq, &src);
if (!ics) {
XICS_DBG("ios_eoi: IRQ 0x%06x not found !\n", irq);
return H_PARAMETER;
}
state = &ics->irq_state[src];
if (state->lsi)
pq_new = state->pq_state;
else
do {
pq_old = state->pq_state;
pq_new = pq_old >> 1;
} while (cmpxchg(&state->pq_state, pq_old, pq_new) != pq_old);
if (pq_new & PQ_PRESENTED)
icp_deliver_irq(xics, icp, irq, false);
kvm_notify_acked_irq(vcpu->kvm, 0, irq);
return H_SUCCESS;
}
static noinline int kvmppc_h_eoi(struct kvm_vcpu *vcpu, unsigned long xirr)
{
struct kvmppc_xics *xics = vcpu->kvm->arch.xics;
struct kvmppc_icp *icp = vcpu->arch.icp;
u32 irq = xirr & 0x00ffffff;
XICS_DBG("h_eoi vcpu %d eoi %#lx\n", vcpu->vcpu_id, xirr);
/*
* ICP State: EOI
*
* Note: If EOI is incorrectly used by SW to lower the CPPR
* value (ie more favored), we do not check for rejection of
* a pending interrupt, this is a SW error and PAPR sepcifies
* that we don't have to deal with it.
*
* The sending of an EOI to the ICS is handled after the
* CPPR update
*
* ICP State: Down_CPPR which we handle
* in a separate function as it's shared with H_CPPR.
*/
icp_down_cppr(xics, icp, xirr >> 24);
/* IPIs have no EOI */
if (irq == XICS_IPI)
return H_SUCCESS;
return ics_eoi(vcpu, irq);
}
KVM: PPC: Book3S HV: Complete passthrough interrupt in host In existing real mode ICP code, when updating the virtual ICP state, if there is a required action that cannot be completely handled in real mode, as for instance, a VCPU needs to be woken up, flags are set in the ICP to indicate the required action. This is checked when returning from hypercalls to decide whether the call needs switch back to the host where the action can be performed in virtual mode. Note that if h_ipi_redirect is enabled, real mode code will first try to message a free host CPU to complete this job instead of returning the host to do it ourselves. Currently, the real mode PCI passthrough interrupt handling code checks if any of these flags are set and simply returns to the host. This is not good enough as the trap value (0x500) is treated as an external interrupt by the host code. It is only when the trap value is a hypercall that the host code searches for and acts on unfinished work by calling kvmppc_xics_rm_complete. This patch introduces a special trap BOOK3S_INTERRUPT_HV_RM_HARD which is returned by KVM if there is unfinished business to be completed in host virtual mode after handling a PCI passthrough interrupt. The host checks for this special interrupt condition and calls into the kvmppc_xics_rm_complete, which is made an exported function for this reason. [paulus@ozlabs.org - moved logic to set r12 to BOOK3S_INTERRUPT_HV_RM_HARD in book3s_hv_rmhandlers.S into the end of kvmppc_check_wake_reason.] Signed-off-by: Suresh Warrier <warrier@linux.vnet.ibm.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2016-08-19 13:35:52 +08:00
int kvmppc_xics_rm_complete(struct kvm_vcpu *vcpu, u32 hcall)
{
struct kvmppc_xics *xics = vcpu->kvm->arch.xics;
struct kvmppc_icp *icp = vcpu->arch.icp;
XICS_DBG("XICS_RM: H_%x completing, act: %x state: %lx tgt: %p\n",
hcall, icp->rm_action, icp->rm_dbgstate.raw, icp->rm_dbgtgt);
if (icp->rm_action & XICS_RM_KICK_VCPU) {
icp->n_rm_kick_vcpu++;
kvmppc_fast_vcpu_kick(icp->rm_kick_target);
}
if (icp->rm_action & XICS_RM_CHECK_RESEND) {
icp->n_rm_check_resend++;
KVM: PPC: Book3S HV: Fix inaccuracies in ICP emulation for H_IPI This fixes some inaccuracies in the state machine for the virtualized ICP when implementing the H_IPI hcall (Set_MFFR and related states): 1. The old code wipes out any pending interrupts when the new MFRR is more favored than the CPPR but less favored than a pending interrupt (by always modifying xisr and the pending_pri). This can cause us to lose a pending external interrupt. The correct code here is to only modify the pending_pri and xisr in the ICP if the MFRR is equal to or more favored than the current pending pri (since in this case, it is guaranteed that that there cannot be a pending external interrupt). The code changes are required in both kvmppc_rm_h_ipi and kvmppc_h_ipi. 2. Again, in both kvmppc_rm_h_ipi and kvmppc_h_ipi, there is a check for whether MFRR is being made less favored AND further if new MFFR is also less favored than the current CPPR, we check for any resends pending in the ICP. These checks look like they are designed to cover the case where if the MFRR is being made less favored, we opportunistically trigger a resend of any interrupts that had been previously rejected. Although, this is not a state described by PAPR, this is an action we actually need to do especially if the CPPR is already at 0xFF. Because in this case, the resend bit will stay on until another ICP state change which may be a long time coming and the interrupt stays pending until then. The current code which checks for MFRR < CPPR is broken when CPPR is 0xFF since it will not get triggered in that case. Ideally, we would want to do a resend only if prio(pending_interrupt) < mfrr && prio(pending_interrupt) < cppr where pending interrupt is the one that was rejected. But we don't have the priority of the pending interrupt state saved, so we simply trigger a resend whenever the MFRR is made less favored. 3. In kvmppc_rm_h_ipi, where we save state to pass resends to the virtual mode, we also need to save the ICP whose need_resend we reset since this does not need to be my ICP (vcpu->arch.icp) as is incorrectly assumed by the current code. A new field rm_resend_icp is added to the kvmppc_icp structure for this purpose. Signed-off-by: Suresh Warrier <warrier@linux.vnet.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-11-03 12:51:59 +08:00
icp_check_resend(xics, icp->rm_resend_icp);
}
if (icp->rm_action & XICS_RM_NOTIFY_EOI) {
icp->n_rm_notify_eoi++;
kvm_notify_acked_irq(vcpu->kvm, 0, icp->rm_eoied_irq);
}
icp->rm_action = 0;
return H_SUCCESS;
}
KVM: PPC: Book3S HV: Complete passthrough interrupt in host In existing real mode ICP code, when updating the virtual ICP state, if there is a required action that cannot be completely handled in real mode, as for instance, a VCPU needs to be woken up, flags are set in the ICP to indicate the required action. This is checked when returning from hypercalls to decide whether the call needs switch back to the host where the action can be performed in virtual mode. Note that if h_ipi_redirect is enabled, real mode code will first try to message a free host CPU to complete this job instead of returning the host to do it ourselves. Currently, the real mode PCI passthrough interrupt handling code checks if any of these flags are set and simply returns to the host. This is not good enough as the trap value (0x500) is treated as an external interrupt by the host code. It is only when the trap value is a hypercall that the host code searches for and acts on unfinished work by calling kvmppc_xics_rm_complete. This patch introduces a special trap BOOK3S_INTERRUPT_HV_RM_HARD which is returned by KVM if there is unfinished business to be completed in host virtual mode after handling a PCI passthrough interrupt. The host checks for this special interrupt condition and calls into the kvmppc_xics_rm_complete, which is made an exported function for this reason. [paulus@ozlabs.org - moved logic to set r12 to BOOK3S_INTERRUPT_HV_RM_HARD in book3s_hv_rmhandlers.S into the end of kvmppc_check_wake_reason.] Signed-off-by: Suresh Warrier <warrier@linux.vnet.ibm.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2016-08-19 13:35:52 +08:00
EXPORT_SYMBOL_GPL(kvmppc_xics_rm_complete);
int kvmppc_xics_hcall(struct kvm_vcpu *vcpu, u32 req)
{
struct kvmppc_xics *xics = vcpu->kvm->arch.xics;
unsigned long res;
int rc = H_SUCCESS;
/* Check if we have an ICP */
if (!xics || !vcpu->arch.icp)
return H_HARDWARE;
/* These requests don't have real-mode implementations at present */
switch (req) {
case H_XIRR_X:
res = kvmppc_h_xirr(vcpu);
kvmppc_set_gpr(vcpu, 4, res);
kvmppc_set_gpr(vcpu, 5, get_tb());
return rc;
case H_IPOLL:
rc = kvmppc_h_ipoll(vcpu, kvmppc_get_gpr(vcpu, 4));
return rc;
}
/* Check for real mode returning too hard */
if (xics->real_mode && is_kvmppc_hv_enabled(vcpu->kvm))
return kvmppc_xics_rm_complete(vcpu, req);
switch (req) {
case H_XIRR:
res = kvmppc_h_xirr(vcpu);
kvmppc_set_gpr(vcpu, 4, res);
break;
case H_CPPR:
kvmppc_h_cppr(vcpu, kvmppc_get_gpr(vcpu, 4));
break;
case H_EOI:
rc = kvmppc_h_eoi(vcpu, kvmppc_get_gpr(vcpu, 4));
break;
case H_IPI:
rc = kvmppc_h_ipi(vcpu, kvmppc_get_gpr(vcpu, 4),
kvmppc_get_gpr(vcpu, 5));
break;
}
return rc;
}
EXPORT_SYMBOL_GPL(kvmppc_xics_hcall);
/* -- Initialisation code etc. -- */
static void xics_debugfs_irqmap(struct seq_file *m,
struct kvmppc_passthru_irqmap *pimap)
{
int i;
if (!pimap)
return;
seq_printf(m, "========\nPIRQ mappings: %d maps\n===========\n",
pimap->n_mapped);
for (i = 0; i < pimap->n_mapped; i++) {
seq_printf(m, "r_hwirq=%x, v_hwirq=%x\n",
pimap->mapped[i].r_hwirq, pimap->mapped[i].v_hwirq);
}
}
static int xics_debug_show(struct seq_file *m, void *private)
{
struct kvmppc_xics *xics = m->private;
struct kvm *kvm = xics->kvm;
struct kvm_vcpu *vcpu;
int icsid, i;
unsigned long flags;
unsigned long t_rm_kick_vcpu, t_rm_check_resend;
unsigned long t_rm_notify_eoi;
unsigned long t_reject, t_check_resend;
if (!kvm)
return 0;
t_rm_kick_vcpu = 0;
t_rm_notify_eoi = 0;
t_rm_check_resend = 0;
t_check_resend = 0;
t_reject = 0;
xics_debugfs_irqmap(m, kvm->arch.pimap);
seq_printf(m, "=========\nICP state\n=========\n");
kvm_for_each_vcpu(i, vcpu, kvm) {
struct kvmppc_icp *icp = vcpu->arch.icp;
union kvmppc_icp_state state;
if (!icp)
continue;
state.raw = READ_ONCE(icp->state.raw);
seq_printf(m, "cpu server %#lx XIRR:%#x PPRI:%#x CPPR:%#x MFRR:%#x OUT:%d NR:%d\n",
icp->server_num, state.xisr,
state.pending_pri, state.cppr, state.mfrr,
state.out_ee, state.need_resend);
t_rm_kick_vcpu += icp->n_rm_kick_vcpu;
t_rm_notify_eoi += icp->n_rm_notify_eoi;
t_rm_check_resend += icp->n_rm_check_resend;
t_check_resend += icp->n_check_resend;
t_reject += icp->n_reject;
}
seq_printf(m, "ICP Guest->Host totals: kick_vcpu=%lu check_resend=%lu notify_eoi=%lu\n",
t_rm_kick_vcpu, t_rm_check_resend,
t_rm_notify_eoi);
seq_printf(m, "ICP Real Mode totals: check_resend=%lu resend=%lu\n",
t_check_resend, t_reject);
for (icsid = 0; icsid <= KVMPPC_XICS_MAX_ICS_ID; icsid++) {
struct kvmppc_ics *ics = xics->ics[icsid];
if (!ics)
continue;
seq_printf(m, "=========\nICS state for ICS 0x%x\n=========\n",
icsid);
local_irq_save(flags);
arch_spin_lock(&ics->lock);
for (i = 0; i < KVMPPC_XICS_IRQ_PER_ICS; i++) {
struct ics_irq_state *irq = &ics->irq_state[i];
seq_printf(m, "irq 0x%06x: server %#x prio %#x save prio %#x pq_state %d resend %d masked pending %d\n",
irq->number, irq->server, irq->priority,
irq->saved_priority, irq->pq_state,
irq->resend, irq->masked_pending);
}
arch_spin_unlock(&ics->lock);
local_irq_restore(flags);
}
return 0;
}
DEFINE_SHOW_ATTRIBUTE(xics_debug);
static void xics_debugfs_init(struct kvmppc_xics *xics)
{
char *name;
name = kasprintf(GFP_KERNEL, "kvm-xics-%p", xics);
if (!name) {
pr_err("%s: no memory for name\n", __func__);
return;
}
xics->dentry = debugfs_create_file(name, 0444, powerpc_debugfs_root,
xics, &xics_debug_fops);
pr_debug("%s: created %s\n", __func__, name);
kfree(name);
}
static struct kvmppc_ics *kvmppc_xics_create_ics(struct kvm *kvm,
struct kvmppc_xics *xics, int irq)
{
struct kvmppc_ics *ics;
int i, icsid;
icsid = irq >> KVMPPC_XICS_ICS_SHIFT;
mutex_lock(&kvm->lock);
/* ICS already exists - somebody else got here first */
if (xics->ics[icsid])
goto out;
/* Create the ICS */
ics = kzalloc(sizeof(struct kvmppc_ics), GFP_KERNEL);
if (!ics)
goto out;
ics->icsid = icsid;
for (i = 0; i < KVMPPC_XICS_IRQ_PER_ICS; i++) {
ics->irq_state[i].number = (icsid << KVMPPC_XICS_ICS_SHIFT) | i;
ics->irq_state[i].priority = MASKED;
ics->irq_state[i].saved_priority = MASKED;
}
smp_wmb();
xics->ics[icsid] = ics;
if (icsid > xics->max_icsid)
xics->max_icsid = icsid;
out:
mutex_unlock(&kvm->lock);
return xics->ics[icsid];
}
static int kvmppc_xics_create_icp(struct kvm_vcpu *vcpu, unsigned long server_num)
{
struct kvmppc_icp *icp;
if (!vcpu->kvm->arch.xics)
return -ENODEV;
if (kvmppc_xics_find_server(vcpu->kvm, server_num))
return -EEXIST;
icp = kzalloc(sizeof(struct kvmppc_icp), GFP_KERNEL);
if (!icp)
return -ENOMEM;
icp->vcpu = vcpu;
icp->server_num = server_num;
icp->state.mfrr = MASKED;
icp->state.pending_pri = MASKED;
vcpu->arch.icp = icp;
XICS_DBG("created server for vcpu %d\n", vcpu->vcpu_id);
return 0;
}
u64 kvmppc_xics_get_icp(struct kvm_vcpu *vcpu)
{
struct kvmppc_icp *icp = vcpu->arch.icp;
union kvmppc_icp_state state;
if (!icp)
return 0;
state = icp->state;
return ((u64)state.cppr << KVM_REG_PPC_ICP_CPPR_SHIFT) |
((u64)state.xisr << KVM_REG_PPC_ICP_XISR_SHIFT) |
((u64)state.mfrr << KVM_REG_PPC_ICP_MFRR_SHIFT) |
((u64)state.pending_pri << KVM_REG_PPC_ICP_PPRI_SHIFT);
}
int kvmppc_xics_set_icp(struct kvm_vcpu *vcpu, u64 icpval)
{
struct kvmppc_icp *icp = vcpu->arch.icp;
struct kvmppc_xics *xics = vcpu->kvm->arch.xics;
union kvmppc_icp_state old_state, new_state;
struct kvmppc_ics *ics;
u8 cppr, mfrr, pending_pri;
u32 xisr;
u16 src;
bool resend;
if (!icp || !xics)
return -ENOENT;
cppr = icpval >> KVM_REG_PPC_ICP_CPPR_SHIFT;
xisr = (icpval >> KVM_REG_PPC_ICP_XISR_SHIFT) &
KVM_REG_PPC_ICP_XISR_MASK;
mfrr = icpval >> KVM_REG_PPC_ICP_MFRR_SHIFT;
pending_pri = icpval >> KVM_REG_PPC_ICP_PPRI_SHIFT;
/* Require the new state to be internally consistent */
if (xisr == 0) {
if (pending_pri != 0xff)
return -EINVAL;
} else if (xisr == XICS_IPI) {
if (pending_pri != mfrr || pending_pri >= cppr)
return -EINVAL;
} else {
if (pending_pri >= mfrr || pending_pri >= cppr)
return -EINVAL;
ics = kvmppc_xics_find_ics(xics, xisr, &src);
if (!ics)
return -EINVAL;
}
new_state.raw = 0;
new_state.cppr = cppr;
new_state.xisr = xisr;
new_state.mfrr = mfrr;
new_state.pending_pri = pending_pri;
/*
* Deassert the CPU interrupt request.
* icp_try_update will reassert it if necessary.
*/
kvmppc_book3s_dequeue_irqprio(icp->vcpu, BOOK3S_INTERRUPT_EXTERNAL);
/*
* Note that if we displace an interrupt from old_state.xisr,
* we don't mark it as rejected. We expect userspace to set
* the state of the interrupt sources to be consistent with
* the ICP states (either before or afterwards, which doesn't
* matter). We do handle resends due to CPPR becoming less
* favoured because that is necessary to end up with a
* consistent state in the situation where userspace restores
* the ICS states before the ICP states.
*/
do {
old_state = READ_ONCE(icp->state);
if (new_state.mfrr <= old_state.mfrr) {
resend = false;
new_state.need_resend = old_state.need_resend;
} else {
resend = old_state.need_resend;
new_state.need_resend = 0;
}
} while (!icp_try_update(icp, old_state, new_state, false));
if (resend)
icp_check_resend(xics, icp);
return 0;
}
static int xics_get_source(struct kvmppc_xics *xics, long irq, u64 addr)
{
int ret;
struct kvmppc_ics *ics;
struct ics_irq_state *irqp;
u64 __user *ubufp = (u64 __user *) addr;
u16 idx;
u64 val, prio;
unsigned long flags;
ics = kvmppc_xics_find_ics(xics, irq, &idx);
if (!ics)
return -ENOENT;
irqp = &ics->irq_state[idx];
local_irq_save(flags);
arch_spin_lock(&ics->lock);
ret = -ENOENT;
if (irqp->exists) {
val = irqp->server;
prio = irqp->priority;
if (prio == MASKED) {
val |= KVM_XICS_MASKED;
prio = irqp->saved_priority;
}
val |= prio << KVM_XICS_PRIORITY_SHIFT;
if (irqp->lsi) {
val |= KVM_XICS_LEVEL_SENSITIVE;
if (irqp->pq_state & PQ_PRESENTED)
val |= KVM_XICS_PENDING;
} else if (irqp->masked_pending || irqp->resend)
val |= KVM_XICS_PENDING;
if (irqp->pq_state & PQ_PRESENTED)
val |= KVM_XICS_PRESENTED;
if (irqp->pq_state & PQ_QUEUED)
val |= KVM_XICS_QUEUED;
ret = 0;
}
arch_spin_unlock(&ics->lock);
local_irq_restore(flags);
if (!ret && put_user(val, ubufp))
ret = -EFAULT;
return ret;
}
static int xics_set_source(struct kvmppc_xics *xics, long irq, u64 addr)
{
struct kvmppc_ics *ics;
struct ics_irq_state *irqp;
u64 __user *ubufp = (u64 __user *) addr;
u16 idx;
u64 val;
u8 prio;
u32 server;
unsigned long flags;
if (irq < KVMPPC_XICS_FIRST_IRQ || irq >= KVMPPC_XICS_NR_IRQS)
return -ENOENT;
ics = kvmppc_xics_find_ics(xics, irq, &idx);
if (!ics) {
ics = kvmppc_xics_create_ics(xics->kvm, xics, irq);
if (!ics)
return -ENOMEM;
}
irqp = &ics->irq_state[idx];
if (get_user(val, ubufp))
return -EFAULT;
server = val & KVM_XICS_DESTINATION_MASK;
prio = val >> KVM_XICS_PRIORITY_SHIFT;
if (prio != MASKED &&
kvmppc_xics_find_server(xics->kvm, server) == NULL)
return -EINVAL;
local_irq_save(flags);
arch_spin_lock(&ics->lock);
irqp->server = server;
irqp->saved_priority = prio;
if (val & KVM_XICS_MASKED)
prio = MASKED;
irqp->priority = prio;
irqp->resend = 0;
irqp->masked_pending = 0;
irqp->lsi = 0;
irqp->pq_state = 0;
if (val & KVM_XICS_LEVEL_SENSITIVE)
irqp->lsi = 1;
/* If PENDING, set P in case P is not saved because of old code */
if (val & KVM_XICS_PRESENTED || val & KVM_XICS_PENDING)
irqp->pq_state |= PQ_PRESENTED;
if (val & KVM_XICS_QUEUED)
irqp->pq_state |= PQ_QUEUED;
irqp->exists = 1;
arch_spin_unlock(&ics->lock);
local_irq_restore(flags);
if (val & KVM_XICS_PENDING)
icp_deliver_irq(xics, NULL, irqp->number, false);
return 0;
}
int kvmppc_xics_set_irq(struct kvm *kvm, int irq_source_id, u32 irq, int level,
bool line_status)
{
struct kvmppc_xics *xics = kvm->arch.xics;
if (!xics)
return -ENODEV;
return ics_deliver_irq(xics, irq, level);
}
static int xics_set_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
{
struct kvmppc_xics *xics = dev->private;
switch (attr->group) {
case KVM_DEV_XICS_GRP_SOURCES:
return xics_set_source(xics, attr->attr, attr->addr);
}
return -ENXIO;
}
static int xics_get_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
{
struct kvmppc_xics *xics = dev->private;
switch (attr->group) {
case KVM_DEV_XICS_GRP_SOURCES:
return xics_get_source(xics, attr->attr, attr->addr);
}
return -ENXIO;
}
static int xics_has_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
{
switch (attr->group) {
case KVM_DEV_XICS_GRP_SOURCES:
if (attr->attr >= KVMPPC_XICS_FIRST_IRQ &&
attr->attr < KVMPPC_XICS_NR_IRQS)
return 0;
break;
}
return -ENXIO;
}
static void kvmppc_xics_free(struct kvm_device *dev)
{
struct kvmppc_xics *xics = dev->private;
int i;
struct kvm *kvm = xics->kvm;
debugfs_remove(xics->dentry);
if (kvm)
kvm->arch.xics = NULL;
for (i = 0; i <= xics->max_icsid; i++)
kfree(xics->ics[i]);
kfree(xics);
kfree(dev);
}
static int kvmppc_xics_create(struct kvm_device *dev, u32 type)
{
struct kvmppc_xics *xics;
struct kvm *kvm = dev->kvm;
int ret = 0;
xics = kzalloc(sizeof(*xics), GFP_KERNEL);
if (!xics)
return -ENOMEM;
dev->private = xics;
xics->dev = dev;
xics->kvm = kvm;
/* Already there ? */
if (kvm->arch.xics)
ret = -EEXIST;
else
kvm->arch.xics = xics;
if (ret) {
kfree(xics);
return ret;
}
#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
if (cpu_has_feature(CPU_FTR_ARCH_206) &&
cpu_has_feature(CPU_FTR_HVMODE)) {
/* Enable real mode support */
xics->real_mode = ENABLE_REALMODE;
xics->real_mode_dbg = DEBUG_REALMODE;
}
#endif /* CONFIG_KVM_BOOK3S_HV_POSSIBLE */
return 0;
}
static void kvmppc_xics_init(struct kvm_device *dev)
{
struct kvmppc_xics *xics = (struct kvmppc_xics *)dev->private;
xics_debugfs_init(xics);
}
struct kvm_device_ops kvm_xics_ops = {
.name = "kvm-xics",
.create = kvmppc_xics_create,
.init = kvmppc_xics_init,
.destroy = kvmppc_xics_free,
.set_attr = xics_set_attr,
.get_attr = xics_get_attr,
.has_attr = xics_has_attr,
};
int kvmppc_xics_connect_vcpu(struct kvm_device *dev, struct kvm_vcpu *vcpu,
u32 xcpu)
{
struct kvmppc_xics *xics = dev->private;
int r = -EBUSY;
if (dev->ops != &kvm_xics_ops)
return -EPERM;
if (xics->kvm != vcpu->kvm)
return -EPERM;
if (vcpu->arch.irq_type)
return -EBUSY;
r = kvmppc_xics_create_icp(vcpu, xcpu);
if (!r)
vcpu->arch.irq_type = KVMPPC_IRQ_XICS;
return r;
}
void kvmppc_xics_free_icp(struct kvm_vcpu *vcpu)
{
if (!vcpu->arch.icp)
return;
kfree(vcpu->arch.icp);
vcpu->arch.icp = NULL;
vcpu->arch.irq_type = KVMPPC_IRQ_DEFAULT;
}
KVM: PPC: Book3S HV: Set server for passed-through interrupts When a guest has a PCI pass-through device with an interrupt, it will direct the interrupt to a particular guest VCPU. In fact the physical interrupt might arrive on any CPU, and then get delivered to the target VCPU in the emulated XICS (guest interrupt controller), and eventually delivered to the target VCPU. Now that we have code to handle device interrupts in real mode without exiting to the host kernel, there is an advantage to having the device interrupt arrive on the same sub(core) as the target VCPU is running on. In this situation, the interrupt can be delivered to the target VCPU without any exit to the host kernel (using a hypervisor doorbell interrupt between threads if necessary). This patch aims to get passed-through device interrupts arriving on the correct core by setting the interrupt server in the real hardware XICS for the interrupt to the first thread in the (sub)core where its target VCPU is running. We do this in the real-mode H_EOI code because the H_EOI handler already needs to look at the emulated ICS state for the interrupt (whereas the H_XIRR handler doesn't), and we know we are running in the target VCPU context at that point. We set the server CPU in hardware using an OPAL call, regardless of what the IRQ affinity mask for the interrupt says, and without updating the affinity mask. This amounts to saying that when an interrupt is passed through to a guest, as a matter of policy we allow the guest's affinity for the interrupt to override the host's. This is inspired by an earlier patch from Suresh Warrier, although none of this code came from that earlier patch. Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2016-08-19 13:35:56 +08:00
void kvmppc_xics_set_mapped(struct kvm *kvm, unsigned long irq,
unsigned long host_irq)
{
struct kvmppc_xics *xics = kvm->arch.xics;
struct kvmppc_ics *ics;
u16 idx;
ics = kvmppc_xics_find_ics(xics, irq, &idx);
if (!ics)
return;
ics->irq_state[idx].host_irq = host_irq;
ics->irq_state[idx].intr_cpu = -1;
}
EXPORT_SYMBOL_GPL(kvmppc_xics_set_mapped);
void kvmppc_xics_clr_mapped(struct kvm *kvm, unsigned long irq,
unsigned long host_irq)
{
struct kvmppc_xics *xics = kvm->arch.xics;
struct kvmppc_ics *ics;
u16 idx;
ics = kvmppc_xics_find_ics(xics, irq, &idx);
if (!ics)
return;
ics->irq_state[idx].host_irq = 0;
}
EXPORT_SYMBOL_GPL(kvmppc_xics_clr_mapped);