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KVM: arm64: Duplicate hyp/tlb.c for VHE/nVHE 

tlb.c contains code for flushing the TLB, with code shared between VHE/nVHE.
Because common code is small, duplicate tlb.c and specialize each copy for
VHE/nVHE.

Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200625131420.71444-9-dbrazdil@google.com
This commit is contained in:
David Brazdil 2020-06-25 14:14:13 +01:00 committed by Marc Zyngier
parent 208243c752
commit e03fa29164
6 changed files with 177 additions and 100 deletions
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14
arch/arm64/kernel/image-vars.h
View File

@ -81,12 +81,6 @@ KVM_NVHE_ALIAS(__kvm_enable_ssbs);
/* Symbols defined in timer-sr.c (not yet compiled with nVHE build rules). */
KVM_NVHE_ALIAS(__kvm_timer_set_cntvoff);
/* Symbols defined in tlb.c (not yet compiled with nVHE build rules). */
KVM_NVHE_ALIAS(__kvm_flush_vm_context);
KVM_NVHE_ALIAS(__kvm_tlb_flush_local_vmid);
KVM_NVHE_ALIAS(__kvm_tlb_flush_vmid);
KVM_NVHE_ALIAS(__kvm_tlb_flush_vmid_ipa);
/* Symbols defined in vgic-v3-sr.c (not yet compiled with nVHE build rules). */
KVM_NVHE_ALIAS(__vgic_v3_get_ich_vtr_el2);
KVM_NVHE_ALIAS(__vgic_v3_init_lrs);
@ -116,6 +110,14 @@ KVM_NVHE_ALIAS(__hyp_stub_vectors);
/* IDMAP TCR_EL1.T0SZ as computed by the EL1 init code */
KVM_NVHE_ALIAS(idmap_t0sz);
/* Kernel symbol used by icache_is_vpipt(). */
KVM_NVHE_ALIAS(__icache_flags);
/* Kernel symbols needed for cpus_have_final/const_caps checks. */
KVM_NVHE_ALIAS(arm64_const_caps_ready);
KVM_NVHE_ALIAS(cpu_hwcap_keys);
KVM_NVHE_ALIAS(cpu_hwcaps);
#endif /* CONFIG_KVM */
#endif /* __ARM64_KERNEL_IMAGE_VARS_H */

2
arch/arm64/kvm/hyp/Makefile
View File

@ -14,7 +14,7 @@ obj-$(CONFIG_KVM) += hyp.o vhe/ nvhe/
obj-$(CONFIG_KVM_INDIRECT_VECTORS) += smccc_wa.o
hyp-y := vgic-v3-sr.o timer-sr.o aarch32.o vgic-v2-cpuif-proxy.o sysreg-sr.o \
debug-sr.o entry.o switch.o fpsimd.o tlb.o
debug-sr.o entry.o switch.o fpsimd.o
# KVM code is run at a different exception code with a different map, so
# compiler instrumentation that inserts callbacks or checks into the code may

2
arch/arm64/kvm/hyp/nvhe/Makefile
View File

@ -6,7 +6,7 @@
asflags-y := -D__KVM_NVHE_HYPERVISOR__
ccflags-y := -D__KVM_NVHE_HYPERVISOR__
obj-y := hyp-init.o ../hyp-entry.o
obj-y := tlb.o hyp-init.o ../hyp-entry.o
obj-y := $(patsubst %.o,%.hyp.o,$(obj-y))
extra-y := $(patsubst %.hyp.o,%.hyp.tmp.o,$(obj-y))

96
arch/arm64/kvm/hyp/tlb.c → arch/arm64/kvm/hyp/nvhe/tlb.c
View File

@ -4,64 +4,16 @@
* Author: Marc Zyngier <marc.zyngier@arm.com>
*/
#include <linux/irqflags.h>
#include <asm/kvm_hyp.h>
#include <asm/kvm_mmu.h>
#include <asm/tlbflush.h>
struct tlb_inv_context {
unsigned long flags;
u64 tcr;
u64 sctlr;
};
static void __hyp_text __tlb_switch_to_guest_vhe(struct kvm *kvm,
struct tlb_inv_context *cxt)
{
u64 val;
local_irq_save(cxt->flags);
if (cpus_have_final_cap(ARM64_WORKAROUND_SPECULATIVE_AT)) {
/*
* For CPUs that are affected by ARM errata 1165522 or 1530923,
* we cannot trust stage-1 to be in a correct state at that
* point. Since we do not want to force a full load of the
* vcpu state, we prevent the EL1 page-table walker to
* allocate new TLBs. This is done by setting the EPD bits
* in the TCR_EL1 register. We also need to prevent it to
* allocate IPA->PA walks, so we enable the S1 MMU...
*/
val = cxt->tcr = read_sysreg_el1(SYS_TCR);
val |= TCR_EPD1_MASK | TCR_EPD0_MASK;
write_sysreg_el1(val, SYS_TCR);
val = cxt->sctlr = read_sysreg_el1(SYS_SCTLR);
val |= SCTLR_ELx_M;
write_sysreg_el1(val, SYS_SCTLR);
}
/*
* With VHE enabled, we have HCR_EL2.{E2H,TGE} = {1,1}, and
* most TLB operations target EL2/EL0. In order to affect the
* guest TLBs (EL1/EL0), we need to change one of these two
* bits. Changing E2H is impossible (goodbye TTBR1_EL2), so
* let's flip TGE before executing the TLB operation.
*
* ARM erratum 1165522 requires some special handling (again),
* as we need to make sure both stages of translation are in
* place before clearing TGE. __load_guest_stage2() already
* has an ISB in order to deal with this.
*/
__load_guest_stage2(kvm);
val = read_sysreg(hcr_el2);
val &= ~HCR_TGE;
write_sysreg(val, hcr_el2);
isb();
}
static void __hyp_text __tlb_switch_to_guest_nvhe(struct kvm *kvm,
struct tlb_inv_context *cxt)
static void __hyp_text __tlb_switch_to_guest(struct kvm *kvm,
struct tlb_inv_context *cxt)
{
if (cpus_have_final_cap(ARM64_WORKAROUND_SPECULATIVE_AT)) {
u64 val;
@ -84,37 +36,8 @@ static void __hyp_text __tlb_switch_to_guest_nvhe(struct kvm *kvm,
asm(ALTERNATIVE("isb", "nop", ARM64_WORKAROUND_SPECULATIVE_AT));
}
static void __hyp_text __tlb_switch_to_guest(struct kvm *kvm,
struct tlb_inv_context *cxt)
{
if (has_vhe())
__tlb_switch_to_guest_vhe(kvm, cxt);
else
__tlb_switch_to_guest_nvhe(kvm, cxt);
}
static void __hyp_text __tlb_switch_to_host_vhe(struct kvm *kvm,
struct tlb_inv_context *cxt)
{
/*
* We're done with the TLB operation, let's restore the host's
* view of HCR_EL2.
*/
write_sysreg(0, vttbr_el2);
write_sysreg(HCR_HOST_VHE_FLAGS, hcr_el2);
isb();
if (cpus_have_final_cap(ARM64_WORKAROUND_SPECULATIVE_AT)) {
/* Restore the registers to what they were */
write_sysreg_el1(cxt->tcr, SYS_TCR);
write_sysreg_el1(cxt->sctlr, SYS_SCTLR);
}
local_irq_restore(cxt->flags);
}
static void __hyp_text __tlb_switch_to_host_nvhe(struct kvm *kvm,
struct tlb_inv_context *cxt)
static void __hyp_text __tlb_switch_to_host(struct kvm *kvm,
struct tlb_inv_context *cxt)
{
write_sysreg(0, vttbr_el2);
@ -126,15 +49,6 @@ static void __hyp_text __tlb_switch_to_host_nvhe(struct kvm *kvm,
}
}
static void __hyp_text __tlb_switch_to_host(struct kvm *kvm,
struct tlb_inv_context *cxt)
{
if (has_vhe())
__tlb_switch_to_host_vhe(kvm, cxt);
else
__tlb_switch_to_host_nvhe(kvm, cxt);
}
void __hyp_text __kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa)
{
struct tlb_inv_context cxt;
@ -183,7 +97,7 @@ void __hyp_text __kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa)
* The moral of this story is: if you have a VPIPT I-cache, then
* you should be running with VHE enabled.
*/
if (!has_vhe() && icache_is_vpipt())
if (icache_is_vpipt())
__flush_icache_all();
__tlb_switch_to_host(kvm, &cxt);

2
arch/arm64/kvm/hyp/vhe/Makefile
View File

@ -6,7 +6,7 @@
asflags-y := -D__KVM_VHE_HYPERVISOR__
ccflags-y := -D__KVM_VHE_HYPERVISOR__
obj-y := ../hyp-entry.o
obj-y := tlb.o ../hyp-entry.o
# KVM code is run at a different exception code with a different map, so
# compiler instrumentation that inserts callbacks or checks into the code may

161
arch/arm64/kvm/hyp/vhe/tlb.c Normal file
View File

@ -0,0 +1,161 @@
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2015 - ARM Ltd
* Author: Marc Zyngier <marc.zyngier@arm.com>
*/
#include <linux/irqflags.h>
#include <asm/kvm_hyp.h>
#include <asm/kvm_mmu.h>
#include <asm/tlbflush.h>
struct tlb_inv_context {
unsigned long flags;
u64 tcr;
u64 sctlr;
};
static void __tlb_switch_to_guest(struct kvm *kvm, struct tlb_inv_context *cxt)
{
u64 val;
local_irq_save(cxt->flags);
if (cpus_have_final_cap(ARM64_WORKAROUND_SPECULATIVE_AT)) {
/*
* For CPUs that are affected by ARM errata 1165522 or 1530923,
* we cannot trust stage-1 to be in a correct state at that
* point. Since we do not want to force a full load of the
* vcpu state, we prevent the EL1 page-table walker to
* allocate new TLBs. This is done by setting the EPD bits
* in the TCR_EL1 register. We also need to prevent it to
* allocate IPA->PA walks, so we enable the S1 MMU...
*/
val = cxt->tcr = read_sysreg_el1(SYS_TCR);
val |= TCR_EPD1_MASK | TCR_EPD0_MASK;
write_sysreg_el1(val, SYS_TCR);
val = cxt->sctlr = read_sysreg_el1(SYS_SCTLR);
val |= SCTLR_ELx_M;
write_sysreg_el1(val, SYS_SCTLR);
}
/*
* With VHE enabled, we have HCR_EL2.{E2H,TGE} = {1,1}, and
* most TLB operations target EL2/EL0. In order to affect the
* guest TLBs (EL1/EL0), we need to change one of these two
* bits. Changing E2H is impossible (goodbye TTBR1_EL2), so
* let's flip TGE before executing the TLB operation.
*
* ARM erratum 1165522 requires some special handling (again),
* as we need to make sure both stages of translation are in
* place before clearing TGE. __load_guest_stage2() already
* has an ISB in order to deal with this.
*/
__load_guest_stage2(kvm);
val = read_sysreg(hcr_el2);
val &= ~HCR_TGE;
write_sysreg(val, hcr_el2);
isb();
}
static void __tlb_switch_to_host(struct kvm *kvm, struct tlb_inv_context *cxt)
{
/*
* We're done with the TLB operation, let's restore the host's
* view of HCR_EL2.
*/
write_sysreg(0, vttbr_el2);
write_sysreg(HCR_HOST_VHE_FLAGS, hcr_el2);
isb();
if (cpus_have_final_cap(ARM64_WORKAROUND_SPECULATIVE_AT)) {
/* Restore the registers to what they were */
write_sysreg_el1(cxt->tcr, SYS_TCR);
write_sysreg_el1(cxt->sctlr, SYS_SCTLR);
}
local_irq_restore(cxt->flags);
}
void __kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa)
{
struct tlb_inv_context cxt;
dsb(ishst);
/* Switch to requested VMID */
__tlb_switch_to_guest(kvm, &cxt);
/*
* We could do so much better if we had the VA as well.
* Instead, we invalidate Stage-2 for this IPA, and the
* whole of Stage-1. Weep...
*/
ipa >>= 12;
__tlbi(ipas2e1is, ipa);
/*
* We have to ensure completion of the invalidation at Stage-2,
* since a table walk on another CPU could refill a TLB with a
* complete (S1 + S2) walk based on the old Stage-2 mapping if
* the Stage-1 invalidation happened first.
*/
dsb(ish);
__tlbi(vmalle1is);
dsb(ish);
isb();
__tlb_switch_to_host(kvm, &cxt);
}
void __kvm_tlb_flush_vmid(struct kvm *kvm)
{
struct tlb_inv_context cxt;
dsb(ishst);
/* Switch to requested VMID */
__tlb_switch_to_guest(kvm, &cxt);
__tlbi(vmalls12e1is);
dsb(ish);
isb();
__tlb_switch_to_host(kvm, &cxt);
}
void __kvm_tlb_flush_local_vmid(struct kvm_vcpu *vcpu)
{
struct kvm *kvm = vcpu->kvm;
struct tlb_inv_context cxt;
/* Switch to requested VMID */
__tlb_switch_to_guest(kvm, &cxt);
__tlbi(vmalle1);
dsb(nsh);
isb();
__tlb_switch_to_host(kvm, &cxt);
}
void __kvm_flush_vm_context(void)
{
dsb(ishst);
__tlbi(alle1is);
/*
* VIPT and PIPT caches are not affected by VMID, so no maintenance
* is necessary across a VMID rollover.
*
* VPIPT caches constrain lookup and maintenance to the active VMID,
* so we need to invalidate lines with a stale VMID to avoid an ABA
* race after multiple rollovers.
*
*/
if (icache_is_vpipt())
asm volatile("ic ialluis");
dsb(ish);
}