The 3 level p2m tree for the Xen tools is constructed very early at
boot by calling xen_build_mfn_list_list(). Memory needed for this tree
is allocated via extend_brk().
As this tree (other than the kernel internal p2m tree) is only needed
for domain save/restore, live migration and crash dump analysis it
doesn't matter whether it is constructed very early or just some
milliseconds later when memory allocation is possible by other means.
This patch moves the call of xen_build_mfn_list_list() just after
calling xen_pagetable_p2m_copy() simplifying this function, too, as it
doesn't have to bother with two parallel trees now. The same applies
for some other internal functions.
While simplifying code, make early_can_reuse_p2m_middle() static and
drop the unused second parameter. p2m_mid_identity_mfn can be removed
as well, it isn't used either.
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Pull percpu consistent-ops changes from Tejun Heo:
"Way back, before the current percpu allocator was implemented, static
and dynamic percpu memory areas were allocated and handled separately
and had their own accessors. The distinction has been gone for many
years now; however, the now duplicate two sets of accessors remained
with the pointer based ones - this_cpu_*() - evolving various other
operations over time. During the process, we also accumulated other
inconsistent operations.
This pull request contains Christoph's patches to clean up the
duplicate accessor situation. __get_cpu_var() uses are replaced with
with this_cpu_ptr() and __this_cpu_ptr() with raw_cpu_ptr().
Unfortunately, the former sometimes is tricky thanks to C being a bit
messy with the distinction between lvalues and pointers, which led to
a rather ugly solution for cpumask_var_t involving the introduction of
this_cpu_cpumask_var_ptr().
This converts most of the uses but not all. Christoph will follow up
with the remaining conversions in this merge window and hopefully
remove the obsolete accessors"
* 'for-3.18-consistent-ops' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (38 commits)
irqchip: Properly fetch the per cpu offset
percpu: Resolve ambiguities in __get_cpu_var/cpumask_var_t -fix
ia64: sn_nodepda cannot be assigned to after this_cpu conversion. Use __this_cpu_write.
percpu: Resolve ambiguities in __get_cpu_var/cpumask_var_t
Revert "powerpc: Replace __get_cpu_var uses"
percpu: Remove __this_cpu_ptr
clocksource: Replace __this_cpu_ptr with raw_cpu_ptr
sparc: Replace __get_cpu_var uses
avr32: Replace __get_cpu_var with __this_cpu_write
blackfin: Replace __get_cpu_var uses
tile: Use this_cpu_ptr() for hardware counters
tile: Replace __get_cpu_var uses
powerpc: Replace __get_cpu_var uses
alpha: Replace __get_cpu_var
ia64: Replace __get_cpu_var uses
s390: cio driver &__get_cpu_var replacements
s390: Replace __get_cpu_var uses
mips: Replace __get_cpu_var uses
MIPS: Replace __get_cpu_var uses in FPU emulator.
arm: Replace __this_cpu_ptr with raw_cpu_ptr
...
This fixes two bugs in PVH guests:
- Not setting EFER.NX means the NX bit in page table entries is
ignored on Intel processors and causes reserved bit page faults on
AMD processors.
- After the Xen commit 7645640d6ff1 ("x86/PVH: don't set EFER_SCE for
pvh guest") PVH guests are required to set EFER.SCE to enable the
SYSCALL instruction.
Secondary VCPUs are started with pagetables with the NX bit set so
EFER.NX must be set before using any stack or data segment.
xen_pvh_cpu_early_init() is the new secondary VCPU entry point that
sets EFER before jumping to cpu_bringup_and_idle().
Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Size restrictions native kernels wouldn't have resulted from the initrd
getting mapped into the initial mapping. The kernel doesn't really need
the initrd to be mapped, so use infrastructure available in Xen to avoid
the mapping and hence the restriction.
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
The _PAGE_IO_MAP PTE flag was only used by Xen PV guests to mark PTEs
that were used to map I/O regions that are 1:1 in the p2m. This
allowed Xen to obtain the correct PFN when converting the MFNs read
from a PTE back to their PFN.
Xen guests no longer use _PAGE_IOMAP for this. Instead mfn_to_pfn()
returns the correct PFN by using a combination of the m2p and p2m to
determine if an MFN corresponds to a 1:1 mapping in the the p2m.
Remove _PAGE_IOMAP, replacing it with _PAGE_UNUSED2 to allow for
future uses of the PTE flag.
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Acked-by: "H. Peter Anvin" <hpa@zytor.com>
__get_cpu_var() is used for multiple purposes in the kernel source. One of
them is address calculation via the form &__get_cpu_var(x). This calculates
the address for the instance of the percpu variable of the current processor
based on an offset.
Other use cases are for storing and retrieving data from the current
processors percpu area. __get_cpu_var() can be used as an lvalue when
writing data or on the right side of an assignment.
__get_cpu_var() is defined as :
#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))
__get_cpu_var() always only does an address determination. However, store
and retrieve operations could use a segment prefix (or global register on
other platforms) to avoid the address calculation.
this_cpu_write() and this_cpu_read() can directly take an offset into a
percpu area and use optimized assembly code to read and write per cpu
variables.
This patch converts __get_cpu_var into either an explicit address
calculation using this_cpu_ptr() or into a use of this_cpu operations that
use the offset. Thereby address calculations are avoided and less registers
are used when code is generated.
Transformations done to __get_cpu_var()
1. Determine the address of the percpu instance of the current processor.
DEFINE_PER_CPU(int, y);
int *x = &__get_cpu_var(y);
Converts to
int *x = this_cpu_ptr(&y);
2. Same as #1 but this time an array structure is involved.
DEFINE_PER_CPU(int, y[20]);
int *x = __get_cpu_var(y);
Converts to
int *x = this_cpu_ptr(y);
3. Retrieve the content of the current processors instance of a per cpu
variable.
DEFINE_PER_CPU(int, y);
int x = __get_cpu_var(y)
Converts to
int x = __this_cpu_read(y);
4. Retrieve the content of a percpu struct
DEFINE_PER_CPU(struct mystruct, y);
struct mystruct x = __get_cpu_var(y);
Converts to
memcpy(&x, this_cpu_ptr(&y), sizeof(x));
5. Assignment to a per cpu variable
DEFINE_PER_CPU(int, y)
__get_cpu_var(y) = x;
Converts to
__this_cpu_write(y, x);
6. Increment/Decrement etc of a per cpu variable
DEFINE_PER_CPU(int, y);
__get_cpu_var(y)++
Converts to
__this_cpu_inc(y)
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86@kernel.org
Acked-by: H. Peter Anvin <hpa@linux.intel.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
- Note that Konrad is xen-blkkback/front maintainer.
- Add 'xen_nopv' option to disable PV extentions for x86 HVM guests.
- Misc. minor cleanups.
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Merge tag 'stable/for-linus-3.17-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull Xen updates from David Vrabel:
- remove unused V2 grant table support
- note that Konrad is xen-blkkback/front maintainer
- add 'xen_nopv' option to disable PV extentions for x86 HVM guests
- misc minor cleanups
* tag 'stable/for-linus-3.17-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
xen-pciback: Document the 'quirks' sysfs file
xen/pciback: Fix error return code in xen_pcibk_attach()
xen/events: drop negativity check of unsigned parameter
xen/setup: Remove Identity Map Debug Message
xen/events/fifo: remove a unecessary use of BM()
xen/events/fifo: ensure all bitops are properly aligned even on x86
xen/events/fifo: reset control block and local HEADs on resume
xen/arm: use BUG_ON
xen/grant-table: remove support for V2 tables
x86/xen: safely map and unmap grant frames when in atomic context
MAINTAINERS: Make me the Xen block subsystem (front and back) maintainer
xen: Introduce 'xen_nopv' to disable PV extensions for HVM guests.
Pull EFI changes from Ingo Molnar:
"Main changes in this cycle are:
- arm64 efi stub fixes, preservation of FP/SIMD registers across
firmware calls, and conversion of the EFI stub code into a static
library - Ard Biesheuvel
- Xen EFI support - Daniel Kiper
- Support for autoloading the efivars driver - Lee, Chun-Yi
- Use the PE/COFF headers in the x86 EFI boot stub to request that
the stub be loaded with CONFIG_PHYSICAL_ALIGN alignment - Michael
Brown
- Consolidate all the x86 EFI quirks into one file - Saurabh Tangri
- Additional error logging in x86 EFI boot stub - Ulf Winkelvos
- Support loading initrd above 4G in EFI boot stub - Yinghai Lu
- EFI reboot patches for ACPI hardware reduced platforms"
* 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (31 commits)
efi/arm64: Handle missing virtual mapping for UEFI System Table
arch/x86/xen: Silence compiler warnings
xen: Silence compiler warnings
x86/efi: Request desired alignment via the PE/COFF headers
x86/efi: Add better error logging to EFI boot stub
efi: Autoload efivars
efi: Update stale locking comment for struct efivars
arch/x86: Remove efi_set_rtc_mmss()
arch/x86: Replace plain strings with constants
xen: Put EFI machinery in place
xen: Define EFI related stuff
arch/x86: Remove redundant set_bit(EFI_MEMMAP) call
arch/x86: Remove redundant set_bit(EFI_SYSTEM_TABLES) call
efi: Introduce EFI_PARAVIRT flag
arch/x86: Do not access EFI memory map if it is not available
efi: Use early_mem*() instead of early_io*()
arch/ia64: Define early_memunmap()
x86/reboot: Add EFI reboot quirk for ACPI Hardware Reduced flag
efi/reboot: Allow powering off machines using EFI
efi/reboot: Add generic wrapper around EfiResetSystem()
...
Compiler complains in the following way when x86 32-bit kernel
with Xen support is build:
CC arch/x86/xen/enlighten.o
arch/x86/xen/enlighten.c: In function ‘xen_start_kernel’:
arch/x86/xen/enlighten.c:1726:3: warning: right shift count >= width of type [enabled by default]
Such line contains following EFI initialization code:
boot_params.efi_info.efi_systab_hi = (__u32)(__pa(efi_systab_xen) >> 32);
There is no issue if x86 64-bit kernel is build. However, 32-bit case
generate warning (even if that code will not be executed because Xen
does not work on 32-bit EFI platforms) due to __pa() returning unsigned long
type which has 32-bits width. So move whole EFI initialization stuff
to separate function and build it conditionally to avoid above mentioned
warning on x86 32-bit architecture.
Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
Reviewed-by: Konrad Rzeszutek Wilk <Konrad.wilk@oracle.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
This patch enables EFI usage under Xen dom0. Standard EFI Linux
Kernel infrastructure cannot be used because it requires direct
access to EFI data and code. However, in dom0 case it is not possible
because above mentioned EFI stuff is fully owned and controlled
by Xen hypervisor. In this case all calls from dom0 to EFI must
be requested via special hypercall which in turn executes relevant
EFI code in behalf of dom0.
When dom0 kernel boots it checks for EFI availability on a machine.
If it is detected then artificial EFI system table is filled.
Native EFI callas are replaced by functions which mimics them
by calling relevant hypercall. Later pointer to EFI system table
is passed to standard EFI machinery and it continues EFI subsystem
initialization taking into account that there is no direct access
to EFI boot services, runtime, tables, structures, etc. After that
system runs as usual.
This patch is based on Jan Beulich and Tang Liang work.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Tang Liang <liang.tang@oracle.com>
Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
By default when CONFIG_XEN and CONFIG_XEN_PVHVM kernels are
run, they will enable the PV extensions (drivers, interrupts, timers,
etc) - which is the best option for the majority of use cases.
However, in some cases (kexec not fully working, benchmarking)
we want to disable Xen PV extensions. As such introduce the
'xen_nopv' parameter that will do it.
This parameter is intended only for HVM guests as the Xen PV
guests MUST boot with PV extensions. However, even if you use
'xen_nopv' on Xen PV guests it will be ignored.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
---
[v2: s/off/xen_nopv/ per Boris Ostrovsky recommendation.]
[v3: Add Reviewed-by]
[v4: Clarify that this is only for HVM guests]
Since af06d66ee32b (x86: fix setup of PVH Dom0 memory map) in Xen, PVH
dom0 need only use the memory memory provided by Xen which has already
setup all the correct holes.
xen_memory_setup() then ends up being trivial for a PVH guest so
introduce a new function (xen_auto_xlated_memory_setup()).
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Tested-by: Roger Pau Monné <roger.pau@citrix.com>
- Support foreign mappings in PVH domains (needed when dom0 is PVH)
- Fix mapping high MMIO regions in x86 PV guests (this is also the
first half of removing the PAGE_IOMAP PTE flag).
- ARM suspend/resume support.
- ARM multicall support.
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Merge tag 'stable/for-linus-3.16-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip into next
Pull Xen updates from David Vrabel:
"xen: features and fixes for 3.16-rc0
- support foreign mappings in PVH domains (needed when dom0 is PVH)
- fix mapping high MMIO regions in x86 PV guests (this is also the
first half of removing the PAGE_IOMAP PTE flag).
- ARM suspend/resume support.
- ARM multicall support"
* tag 'stable/for-linus-3.16-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
x86/xen: map foreign pfns for autotranslated guests
xen-acpi-processor: Don't display errors when we get -ENOSYS
xen/pciback: Document the entry points for 'pcistub_put_pci_dev'
xen/pciback: Document when the 'unbind' and 'bind' functions are called.
xen-pciback: Document when we FLR an PCI device.
xen-pciback: First reset, then free.
xen-pciback: Cleanup up pcistub_put_pci_dev
x86/xen: do not use _PAGE_IOMAP in xen_remap_domain_mfn_range()
x86/xen: set regions above the end of RAM as 1:1
x86/xen: only warn once if bad MFNs are found during setup
x86/xen: compactly store large identity ranges in the p2m
x86/xen: fix set_phys_range_identity() if pfn_e > MAX_P2M_PFN
x86/xen: rename early_p2m_alloc() and early_p2m_alloc_middle()
xen/x86: set panic notifier priority to minimum
arm,arm64/xen: introduce HYPERVISOR_suspend()
xen: refactor suspend pre/post hooks
arm: xen: export HYPERVISOR_multicall to modules.
arm64: introduce virt_to_pfn
arm/xen: Remove definiition of virt_to_pfn in asm/xen/page.h
arm: xen: implement multicall hypercall support.
Execution is not going to continue after telling Xen about the crash.
Let other panic notifiers run by postponing the final hypercall as much
as possible.
Signed-off-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
As requested by Linus add explicit __visible to the asmlinkage users.
This marks all functions visible to assembler.
Tree sweep for arch/x86/*
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Link: http://lkml.kernel.org/r/1398984278-29319-3-git-send-email-andi@firstfloor.org
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
During bootup in the 'probe_page_size_mask' these CR4 flags are
set in there. But for AP processors they are not set as we do not
use 'secondary_startup_64' which the baremetal kernels uses.
Instead do it in this function which we use in Xen PVH during our
startup for AP processors.
As such fix it up to make sure we have that flag set.
Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
otherwise we will get for some user-space applications
that use 'clone' with CLONE_CHILD_SETTID | CLONE_CHILD_CLEARTID
end up hitting an assert in glibc manifested by:
general protection ip:7f80720d364c sp:7fff98fd8a80 error:0 in
libc-2.13.so[7f807209e000+180000]
This is due to the nature of said operations which sets and clears
the PID. "In the successful one I can see that the page table of
the parent process has been updated successfully to use a
different physical page, so the write of the tid on
that page only affects the child...
On the other hand, in the failed case, the write seems to happen before
the copy of the original page is done, so both the parent and the child
end up with the same value (because the parent copies the page after
the write of the child tid has already happened)."
(Roger's analysis). The nature of this is due to the Xen's commit
of 51e2cac257ec8b4080d89f0855c498cbbd76a5e5
"x86/pvh: set only minimal cr0 and cr4 flags in order to use paging"
the CR0_WP was removed so COW features of the Linux kernel were not
operating properly.
While doing that also update the rest of the CR0 flags to be inline
with what a baremetal Linux kernel would set them to.
In 'secondary_startup_64' (baremetal Linux) sets:
X86_CR0_PE | X86_CR0_MP | X86_CR0_ET | X86_CR0_NE | X86_CR0_WP |
X86_CR0_AM | X86_CR0_PG
The hypervisor for HVM type guests (which PVH is a bit) sets:
X86_CR0_PE | X86_CR0_ET | X86_CR0_TS
For PVH it specifically sets:
X86_CR0_PG
Which means we need to set the rest: X86_CR0_MP | X86_CR0_NE |
X86_CR0_WP | X86_CR0_AM to have full parity.
Signed-off-by: Roger Pau Monne <roger.pau@citrix.com>
Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
[v1: Took out the cr4 writes to be a seperate patch]
[v2: 0-DAY kernel found xen_setup_gdt to be missing a static]
PVH is a PV guest with a twist - there are certain things
that work in it like HVM and some like PV. There is
a similar mode - PVHVM where we run in HVM mode with
PV code enabled - and this patch explores that.
The most notable PV interfaces are the XenBus and event channels.
We will piggyback on how the event channel mechanism is
used in PVHVM - that is we want the normal native IRQ mechanism
and we will install a vector (hvm callback) for which we
will call the event channel mechanism.
This means that from a pvops perspective, we can use
native_irq_ops instead of the Xen PV specific. Albeit in the
future we could support pirq_eoi_map. But that is
a feature request that can be shared with PVHVM.
Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
The VCPU bringup protocol follows the PV with certain twists.
From xen/include/public/arch-x86/xen.h:
Also note that when calling DOMCTL_setvcpucontext and VCPU_initialise
for HVM and PVH guests, not all information in this structure is updated:
- For HVM guests, the structures read include: fpu_ctxt (if
VGCT_I387_VALID is set), flags, user_regs, debugreg[*]
- PVH guests are the same as HVM guests, but additionally use ctrlreg[3] to
set cr3. All other fields not used should be set to 0.
This is what we do. We piggyback on the 'xen_setup_gdt' - but modify
a bit - we need to call 'load_percpu_segment' so that 'switch_to_new_gdt'
can load per-cpu data-structures. It has no effect on the VCPU0.
We also piggyback on the %rdi register to pass in the CPU number - so
that when we bootup a new CPU, the cpu_bringup_and_idle will have
passed as the first parameter the CPU number (via %rdi for 64-bit).
Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
During early bootup we start life using the Xen provided
GDT, which means that we are running with %cs segment set
to FLAT_KERNEL_CS (FLAT_RING3_CS64 0xe033, GDT index 261).
But for PVH we want to be use HVM type mechanism for
segment operations. As such we need to switch to the HVM
one and also reload ourselves with the __KERNEL_CS:eip
to run in the proper GDT and segment.
For HVM this is usually done in 'secondary_startup_64' in
(head_64.S) but since we are not taking that bootup
path (we start in PV - xen_start_kernel) we need to do
that in the early PV bootup paths.
For good measure we also zero out the %fs, %ds, and %es
(not strictly needed as Xen has already cleared them
for us). The %gs is loaded by 'switch_to_new_gdt'.
Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
P2M is not available for PVH. Fortunatly for us the
P2M code already has mostly the support for auto-xlat guest thanks to
commit 3d24bbd7dd
"grant-table: call set_phys_to_machine after mapping grant refs"
which: "
introduces set_phys_to_machine calls for auto_translated guests
(even on x86) in gnttab_map_refs and gnttab_unmap_refs.
translated by swiotlb-xen... " so we don't need to muck much.
with above mentioned "commit you'll get set_phys_to_machine calls
from gnttab_map_refs and gnttab_unmap_refs but PVH guests won't do
anything with them " (Stefano Stabellini) which is OK - we want
them to be NOPs.
This is because we assume that an "IOMMU is always present on the
plaform and Xen is going to make the appropriate IOMMU pagetable
changes in the hypercall implementation of GNTTABOP_map_grant_ref
and GNTTABOP_unmap_grant_ref, then eveything should be transparent
from PVH priviligied point of view and DMA transfers involving
foreign pages keep working with no issues[sp]
Otherwise we would need a P2M (and an M2P) for PVH priviligied to
track these foreign pages .. (see arch/arm/xen/p2m.c)."
(Stefano Stabellini).
We still have to inhibit the building of the P2M tree.
That had been done in the past by not calling
xen_build_dynamic_phys_to_machine (which setups the P2M tree
and gives us virtual address to access them). But we are missing
a check for xen_build_mfn_list_list - which was continuing to setup
the P2M tree and would blow up at trying to get the virtual
address of p2m_missing (which would have been setup by
xen_build_dynamic_phys_to_machine).
Hence a check is needed to not call xen_build_mfn_list_list when
running in auto-xlat mode.
Instead of replicating the check for auto-xlat in enlighten.c
do it in the p2m.c code. The reason is that the xen_build_mfn_list_list
is called also in xen_arch_post_suspend without any checks for
auto-xlat. So for PVH or PV with auto-xlat - we would needlessly
allocate space for an P2M tree.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
We don't use the filtering that 'xen_cpuid' is doing
because the hypervisor treats 'XEN_EMULATE_PREFIX' as
an invalid instruction. This means that all of the filtering
will have to be done in the hypervisor/toolstack.
Without the filtering we expose to the guest the:
- cpu topology (sockets, cores, etc);
- the APERF (which the generic scheduler likes to
use), see 5e62625420
"xen/setup: filter APERFMPERF cpuid feature out"
- and the inability to figure out whether MWAIT_LEAF
should be exposed or not. See
df88b2d96e
"xen/enlighten: Disable MWAIT_LEAF so that acpi-pad won't be loaded."
- x2apic, see 4ea9b9aca9
"xen: mask x2APIC feature in PV"
We also check for vector callback early on, as it is a required
feature. PVH also runs at default kernel IOPL.
Finally, pure PV settings are moved to a separate function that are
only called for pure PV, ie, pv with pvmmu. They are also #ifdef
with CONFIG_XEN_PVMMU.
Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
- Boot on ARM without using Xen unconditionally
- On Xen ARM don't run cpuidle/cpufreq
- Fix regression in balloon driver, preempt count warnings
- Fixes to make PVHVM able to use pv ticketlock.
- Revert Xen PVHVM disabling pv ticketlock (aka, re-enable pv ticketlocks)
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Merge tag 'stable/for-linus-3.12-rc0-tag-two' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull Xen bug-fixes from Konrad Rzeszutek Wilk:
"This pull I usually do after rc1 is out but because we have a nice
amount of fixes, some bootup related fixes for ARM, and it is early in
the cycle we figured to do it now to help with tracking of potential
regressions.
The simple ones are the ARM ones - one of the patches fell through the
cracks, other fixes a bootup issue (unconditionally using Xen
functions). Then a fix for a regression causing preempt count being
off (patch causing this went in v3.12).
Lastly are the fixes to make Xen PVHVM guests use PV ticketlocks (Xen
PV already does).
The enablement of that was supposed to be part of the x86 spinlock
merge in commit 816434ec4a ("The biggest change here are
paravirtualized ticket spinlocks (PV spinlocks), which bring a nice
speedup on various benchmarks...") but unfortunatly it would cause
hang when booting Xen PVHVM guests. Yours truly got all of the bugs
fixed last week and they (six of them) are included in this pull.
Bug-fixes:
- Boot on ARM without using Xen unconditionally
- On Xen ARM don't run cpuidle/cpufreq
- Fix regression in balloon driver, preempt count warnings
- Fixes to make PVHVM able to use pv ticketlock.
- Revert Xen PVHVM disabling pv ticketlock (aka, re-enable pv ticketlocks)"
* tag 'stable/for-linus-3.12-rc0-tag-two' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
xen/spinlock: Don't use __initdate for xen_pv_spin
Revert "xen/spinlock: Disable IRQ spinlock (PV) allocation on PVHVM"
xen/spinlock: Don't setup xen spinlock IPI kicker if disabled.
xen/smp: Update pv_lock_ops functions before alternative code starts under PVHVM
xen/spinlock: We don't need the old structure anymore
xen/spinlock: Fix locking path engaging too soon under PVHVM.
xen/arm: disable cpuidle and cpufreq when linux is running as dom0
xen/p2m: Don't call get_balloon_scratch_page() twice, keep interrupts disabled for multicalls
ARM: xen: only set pm function ptrs for Xen guests
The xen_lock_spinning has a check for the kicker interrupts
and if it is not initialized it will spin normally (not enter
the slowpath).
But for PVHVM case we would initialize the kicker interrupt
before the CPU came online. This meant that if the booting
CPU used a spinlock and went in the slowpath - it would
enter the slowpath and block forever. The forever part because
during bootup: the spinlock would be taken _before_ the CPU
sets itself to be online (more on this further), and we enter
to poll on the event channel forever.
The bootup CPU (see commit fc78d343fa
"xen/smp: initialize IPI vectors before marking CPU online"
for details) and the CPU that started the bootup consult
the cpu_online_mask to determine whether the booting CPU should
get an IPI. The booting CPU has to set itself in this mask via:
set_cpu_online(smp_processor_id(), true);
However, if the spinlock is taken before this (and it is) and
it polls on an event channel - it will never be woken up as
the kernel will never send an IPI to an offline CPU.
Note that the PVHVM logic in sending IPIs is using the HVM
path which has numerous checks using the cpu_online_mask
and cpu_active_mask. See above mention git commit for details.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
- Xen Trusted Platform Module (TPM) frontend driver - with the backend in MiniOS.
- Scalability improvements in event channel.
- Two extra Xen co-maintainers (David, Boris) and one going away (Jeremy)
Bug-fixes:
- Make the 1:1 mapping work during early bootup on selective regions.
- Add scratch page to balloon driver to deal with unexpected code still holding
on stale pages.
- Allow NMIs on PV guests (64-bit only)
- Remove unnecessary TLB flush in M2P code.
- Fixes duplicate callbacks in Xen granttable code.
- Fixes in PRIVCMD_MMAPBATCH ioctls to allow retries
- Fix for events being lost due to rescheduling on different VCPUs.
- More documentation.
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Merge tag 'stable/for-linus-3.12-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull Xen updates from Konrad Rzeszutek Wilk:
"A couple of features and a ton of bug-fixes. There is also some
maintership changes. Jeremy is enjoying the full-time work at the
startup and as much as he would love to help - he can't find the time.
I have a bunch of other things that I promised to work on - paravirt
diet, get SWIOTLB working everywhere, etc, but haven't been able to
find the time.
As such both David Vrabel and Boris Ostrovsky have graciously
volunteered to help with the maintership role. They will keep the lid
on regressions, bug-fixes, etc. I will be in the background to help -
but eventually there will be less of me doing the Xen GIT pulls and
more of them. Stefano is still doing the ARM/ARM64 and will continue
on doing so.
Features:
- Xen Trusted Platform Module (TPM) frontend driver - with the
backend in MiniOS.
- Scalability improvements in event channel.
- Two extra Xen co-maintainers (David, Boris) and one going away (Jeremy)
Bug-fixes:
- Make the 1:1 mapping work during early bootup on selective regions.
- Add scratch page to balloon driver to deal with unexpected code
still holding on stale pages.
- Allow NMIs on PV guests (64-bit only)
- Remove unnecessary TLB flush in M2P code.
- Fixes duplicate callbacks in Xen granttable code.
- Fixes in PRIVCMD_MMAPBATCH ioctls to allow retries
- Fix for events being lost due to rescheduling on different VCPUs.
- More documentation"
* tag 'stable/for-linus-3.12-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: (23 commits)
hvc_xen: Remove unnecessary __GFP_ZERO from kzalloc
drivers/xen-tpmfront: Fix compile issue with missing option.
xen/balloon: don't set P2M entry for auto translated guest
xen/evtchn: double free on error
Xen: Fix retry calls into PRIVCMD_MMAPBATCH*.
xen/pvhvm: Initialize xen panic handler for PVHVM guests
xen/m2p: use GNTTABOP_unmap_and_replace to reinstate the original mapping
xen: fix ARM build after 6efa20e4
MAINTAINERS: Remove Jeremy from the Xen subsystem.
xen/events: document behaviour when scanning the start word for events
x86/xen: during early setup, only 1:1 map the ISA region
x86/xen: disable premption when enabling local irqs
swiotlb-xen: replace dma_length with sg_dma_len() macro
swiotlb: replace dma_length with sg_dma_len() macro
xen/balloon: set a mapping for ballooned out pages
xen/evtchn: improve scalability by using per-user locks
xen/p2m: avoid unneccesary TLB flush in m2p_remove_override()
MAINTAINERS: Add in two extra co-maintainers of the Xen tree.
MAINTAINERS: Update the Xen subsystem's with proper mailing list.
xen: replace strict_strtoul() with kstrtoul()
...
kernel use callback linked in panic_notifier_list to notice others when panic
happens.
NORET_TYPE void panic(const char * fmt, ...){
...
atomic_notifier_call_chain(&panic_notifier_list, 0, buf);
}
When Xen becomes aware of this, it will call xen_reboot(SHUTDOWN_crash) to
send out an event with reason code - SHUTDOWN_crash.
xen_panic_handler_init() is defined to register on panic_notifier_list but
we only call it in xen_arch_setup which only be called by PV, this patch is
necessary for PVHVM.
Without this patch, setting 'on_crash=coredump-restart' in PVHVM guest config
file won't lead a vmcore to be generate when the guest panics. It can be
reproduced with 'echo c > /proc/sysrq-trigger'.
Signed-off-by: Vaughan Cao <vaughan.cao@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Joe Jin <joe.jin@oracle.com>
This is based on a patch that Zhenzhong Duan had sent - which
was missing some of the remaining pieces. The kernel has the
logic to handle Xen-type-exceptions using the paravirt interface
in the assembler code (see PARAVIRT_ADJUST_EXCEPTION_FRAME -
pv_irq_ops.adjust_exception_frame and and INTERRUPT_RETURN -
pv_cpu_ops.iret).
That means the nmi handler (and other exception handlers) use
the hypervisor iret.
The other changes that would be neccessary for this would
be to translate the NMI_VECTOR to one of the entries on the
ipi_vector and make xen_send_IPI_mask_allbutself use different
events.
Fortunately for us commit 1db01b4903
(xen: Clean up apic ipi interface) implemented this and we piggyback
on the cleanup such that the apic IPI interface will pass the right
vector value for NMI.
With this patch we can trigger NMIs within a PV guest (only tested
x86_64).
For this to work with normal PV guests (not initial domain)
we need the domain to be able to use the APIC ops - they are
already implemented to use the Xen event channels. For that
to be turned on in a PV domU we need to remove the masking
of X86_FEATURE_APIC.
Incidentally that means kgdb will also now work within
a PV guest without using the 'nokgdbroundup' workaround.
Note that the 32-bit version is different and this patch
does not enable that.
CC: Lisa Nguyen <lisa@xenapiadmin.com>
CC: Ben Guthro <benjamin.guthro@citrix.com>
CC: Zhenzhong Duan <zhenzhong.duan@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
[v1: Fixed up per David Vrabel comments]
Reviewed-by: Ben Guthro <benjamin.guthro@citrix.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
We try to handle the hypervisor compatibility mode by detecting hypervisor
through a specific order. This is not robust, since hypervisors may implement
each others features.
This patch tries to handle this situation by always choosing the last one in the
CPUID leaves. This is done by letting .detect() return a priority instead of
true/false and just re-using the CPUID leaf where the signature were found as
the priority (or 1 if it was found by DMI). Then we can just pick hypervisor who
has the highest priority. Other sophisticated detection method could also be
implemented on top.
Suggested by H. Peter Anvin and Paolo Bonzini.
Acked-by: K. Y. Srinivasan <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Doug Covelli <dcovelli@vmware.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Dan Hecht <dhecht@vmware.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Gleb Natapov <gleb@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: http://lkml.kernel.org/r/1374742475-2485-4-git-send-email-jasowang@redhat.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
The __cpuinit type of throwaway sections might have made sense
some time ago when RAM was more constrained, but now the savings
do not offset the cost and complications. For example, the fix in
commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time")
is a good example of the nasty type of bugs that can be created
with improper use of the various __init prefixes.
After a discussion on LKML[1] it was decided that cpuinit should go
the way of devinit and be phased out. Once all the users are gone,
we can then finally remove the macros themselves from linux/init.h.
Note that some harmless section mismatch warnings may result, since
notify_cpu_starting() and cpu_up() are arch independent (kernel/cpu.c)
are flagged as __cpuinit -- so if we remove the __cpuinit from
arch specific callers, we will also get section mismatch warnings.
As an intermediate step, we intend to turn the linux/init.h cpuinit
content into no-ops as early as possible, since that will get rid
of these warnings. In any case, they are temporary and harmless.
This removes all the arch/x86 uses of the __cpuinit macros from
all C files. x86 only had the one __CPUINIT used in assembly files,
and it wasn't paired off with a .previous or a __FINIT, so we can
delete it directly w/o any corresponding additional change there.
[1] https://lkml.org/lkml/2013/5/20/589
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Reimplement FPU detection code in C and drop old, not-so-recommended
detection method in asm. Move all the relevant stuff into i387.c where
it conceptually belongs. Finally drop cpuinfo_x86.hard_math.
[ hpa: huge thanks to Borislav for taking my original concept patch
and productizing it ]
[ Boris, note to self: do not use static_cpu_has before alternatives! ]
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/r/1367244262-29511-2-git-send-email-bp@alien8.de
Link: http://lkml.kernel.org/r/1365436666-9837-2-git-send-email-bp@alien8.de
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
- More fixes in the vCPU PVHVM hotplug path.
- Add more documentation.
- Fix various ARM related issues in the Xen generic drivers.
- Updates in the xen-pciback driver per Bjorn's updates.
- Mask the x2APIC feature for PV guests.
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Merge tag 'stable/for-linus-3.10-rc0-tag-two' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen
Pull Xen bug-fixes from Konrad Rzeszutek Wilk:
- More fixes in the vCPU PVHVM hotplug path.
- Add more documentation.
- Fix various ARM related issues in the Xen generic drivers.
- Updates in the xen-pciback driver per Bjorn's updates.
- Mask the x2APIC feature for PV guests.
* tag 'stable/for-linus-3.10-rc0-tag-two' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
xen/pci: Used cached MSI-X capability offset
xen/pci: Use PCI_MSIX_TABLE_BIR, not PCI_MSIX_FLAGS_BIRMASK
xen: clear IRQ_NOAUTOEN and IRQ_NOREQUEST
xen: mask x2APIC feature in PV
xen: SWIOTLB is only used on x86
xen/spinlock: Fix check from greater than to be also be greater or equal to.
xen/smp/pvhvm: Don't point per_cpu(xen_vpcu, 33 and larger) to shared_info
xen/vcpu: Document the xen_vcpu_info and xen_vcpu
xen/vcpu/pvhvm: Fix vcpu hotplugging hanging.
As it will point to some data, but not event channel data (the
shared_info has an array limited to 32).
This means that for PVHVM guests with more than 32 VCPUs without
the usage of VCPUOP_register_info any interrupts to VCPUs
larger than 32 would have gone unnoticed during early bootup.
That is OK, as during early bootup, in smp_init we end up calling
the hotplug mechanism (xen_hvm_cpu_notify) which makes the
VCPUOP_register_vcpu_info call for all VCPUs and we can receive
interrupts on VCPUs 33 and further.
This is just a cleanup.
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
They are important structures and it is not clear at first
look what they are for.
The xen_vcpu is a pointer. By default it points to the shared_info
structure (at the CPU offset location). However if the
VCPUOP_register_vcpu_info hypercall is implemented we can make the
xen_vcpu pointer point to a per-CPU location.
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
[v1: Added comments from Ian Campbell]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
If a user did:
echo 0 > /sys/devices/system/cpu/cpu1/online
echo 1 > /sys/devices/system/cpu/cpu1/online
we would (this a build with DEBUG enabled) get to:
smpboot: ++++++++++++++++++++=_---CPU UP 1
.. snip..
smpboot: Stack at about ffff880074c0ff44
smpboot: CPU1: has booted.
and hang. The RCU mechanism would kick in an try to IPI the CPU1
but the IPIs (and all other interrupts) would never arrive at the
CPU1. At first glance at least. A bit digging in the hypervisor
trace shows that (using xenanalyze):
[vla] d4v1 vec 243 injecting
0.043163027 --|x d4v1 intr_window vec 243 src 5(vector) intr f3
] 0.043163639 --|x d4v1 vmentry cycles 1468
] 0.043164913 --|x d4v1 vmexit exit_reason PENDING_INTERRUPT eip ffffffff81673254
0.043164913 --|x d4v1 inj_virq vec 243 real
[vla] d4v1 vec 243 injecting
0.043164913 --|x d4v1 intr_window vec 243 src 5(vector) intr f3
] 0.043165526 --|x d4v1 vmentry cycles 1472
] 0.043166800 --|x d4v1 vmexit exit_reason PENDING_INTERRUPT eip ffffffff81673254
0.043166800 --|x d4v1 inj_virq vec 243 real
[vla] d4v1 vec 243 injecting
there is a pending event (subsequent debugging shows it is the IPI
from the VCPU0 when smpboot.c on VCPU1 has done
"set_cpu_online(smp_processor_id(), true)") and the guest VCPU1 is
interrupted with the callback IPI (0xf3 aka 243) which ends up calling
__xen_evtchn_do_upcall.
The __xen_evtchn_do_upcall seems to do *something* but not acknowledge
the pending events. And the moment the guest does a 'cli' (that is the
ffffffff81673254 in the log above) the hypervisor is invoked again to
inject the IPI (0xf3) to tell the guest it has pending interrupts.
This repeats itself forever.
The culprit was the per_cpu(xen_vcpu, cpu) pointer. At the bootup
we set each per_cpu(xen_vcpu, cpu) to point to the
shared_info->vcpu_info[vcpu] but later on use the VCPUOP_register_vcpu_info
to register per-CPU structures (xen_vcpu_setup).
This is used to allow events for more than 32 VCPUs and for performance
optimizations reasons.
When the user performs the VCPU hotplug we end up calling the
the xen_vcpu_setup once more. We make the hypercall which returns
-EINVAL as it does not allow multiple registration calls (and
already has re-assigned where the events are being set). We pick
the fallback case and set per_cpu(xen_vcpu, cpu) to point to the
shared_info->vcpu_info[vcpu] (which is a good fallback during bootup).
However the hypervisor is still setting events in the register
per-cpu structure (per_cpu(xen_vcpu_info, cpu)).
As such when the events are set by the hypervisor (such as timer one),
and when we iterate in __xen_evtchn_do_upcall we end up reading stale
events from the shared_info->vcpu_info[vcpu] instead of the
per_cpu(xen_vcpu_info, cpu) structures. Hence we never acknowledge the
events that the hypervisor has set and the hypervisor keeps on reminding
us to ack the events which we never do.
The fix is simple. Don't on the second time when xen_vcpu_setup is
called over-write the per_cpu(xen_vcpu, cpu) if it points to
per_cpu(xen_vcpu_info).
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
CC: stable@vger.kernel.org
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Pull x86 paravirt update from Ingo Molnar:
"Various paravirtualization related changes - the biggest one makes
guest support optional via CONFIG_HYPERVISOR_GUEST"
* 'x86-paravirt-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, wakeup, sleep: Use pvops functions for changing GDT entries
x86, xen, gdt: Remove the pvops variant of store_gdt.
x86-32, gdt: Store/load GDT for ACPI S3 or hibernation/resume path is not needed
x86-64, gdt: Store/load GDT for ACPI S3 or hibernate/resume path is not needed.
x86: Make Linux guest support optional
x86, Kconfig: Move PARAVIRT_DEBUG into the paravirt menu
When we online the CPU, we get this splat:
smpboot: Booting Node 0 Processor 1 APIC 0x2
installing Xen timer for CPU 1
BUG: sleeping function called from invalid context at /home/konrad/ssd/konrad/linux/mm/slab.c:3179
in_atomic(): 1, irqs_disabled(): 0, pid: 0, name: swapper/1
Pid: 0, comm: swapper/1 Not tainted 3.9.0-rc6upstream-00001-g3884fad #1
Call Trace:
[<ffffffff810c1fea>] __might_sleep+0xda/0x100
[<ffffffff81194617>] __kmalloc_track_caller+0x1e7/0x2c0
[<ffffffff81303758>] ? kasprintf+0x38/0x40
[<ffffffff813036eb>] kvasprintf+0x5b/0x90
[<ffffffff81303758>] kasprintf+0x38/0x40
[<ffffffff81044510>] xen_setup_timer+0x30/0xb0
[<ffffffff810445af>] xen_hvm_setup_cpu_clockevents+0x1f/0x30
[<ffffffff81666d0a>] start_secondary+0x19c/0x1a8
The solution to that is use kasprintf in the CPU hotplug path
that 'online's the CPU. That is, do it in in xen_hvm_cpu_notify,
and remove the call to in xen_hvm_setup_cpu_clockevents.
Unfortunatly the later is not a good idea as the bootup path
does not use xen_hvm_cpu_notify so we would end up never allocating
timer%d interrupt lines when booting. As such add the check for
atomic() to continue.
CC: stable@vger.kernel.org
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
During early setup of a dom0 kernel, populate boot_params with the
Enhanced Disk Drive (EDD) and MBR signature data. This makes
information on the BIOS boot device available in /sys/firmware/edd/.
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
The two use-cases where we needed to store the GDT were during ACPI S3 suspend
and resume. As the patches:
x86/gdt/i386: store/load GDT for ACPI S3 or hibernation/resume path is not needed
x86/gdt/64-bit: store/load GDT for ACPI S3 or hibernate/resume path is not needed.
have demonstrated - there are other mechanism by which the GDT is
saved and reloaded during early resume path.
Hence we do not need to worry about the pvops call-chain for saving the
GDT and can and can eliminate it. The other areas where the store_gdt is
used are never going to be hit when running under the pvops platforms.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Link: http://lkml.kernel.org/r/1365194544-14648-4-git-send-email-konrad.wilk@oracle.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
The git commit 8eaffa67b4
(xen/pat: Disable PAT support for now) explains in details why
we want to disable PAT for right now. However that
change was not enough and we should have also disabled
the pat_enabled value. Otherwise we end up with:
mmap-example:3481 map pfn expected mapping type write-back for
[mem 0x00010000-0x00010fff], got uncached-minus
------------[ cut here ]------------
WARNING: at /build/buildd/linux-3.8.0/arch/x86/mm/pat.c:774 untrack_pfn+0xb8/0xd0()
mem 0x00010000-0x00010fff], got uncached-minus
------------[ cut here ]------------
WARNING: at /build/buildd/linux-3.8.0/arch/x86/mm/pat.c:774
untrack_pfn+0xb8/0xd0()
...
Pid: 3481, comm: mmap-example Tainted: GF 3.8.0-6-generic #13-Ubuntu
Call Trace:
[<ffffffff8105879f>] warn_slowpath_common+0x7f/0xc0
[<ffffffff810587fa>] warn_slowpath_null+0x1a/0x20
[<ffffffff8104bcc8>] untrack_pfn+0xb8/0xd0
[<ffffffff81156c1c>] unmap_single_vma+0xac/0x100
[<ffffffff81157459>] unmap_vmas+0x49/0x90
[<ffffffff8115f808>] exit_mmap+0x98/0x170
[<ffffffff810559a4>] mmput+0x64/0x100
[<ffffffff810560f5>] dup_mm+0x445/0x660
[<ffffffff81056d9f>] copy_process.part.22+0xa5f/0x1510
[<ffffffff81057931>] do_fork+0x91/0x350
[<ffffffff81057c76>] sys_clone+0x16/0x20
[<ffffffff816ccbf9>] stub_clone+0x69/0x90
[<ffffffff816cc89d>] ? system_call_fastpath+0x1a/0x1f
---[ end trace 4918cdd0a4c9fea4 ]---
(a similar message shows up if you end up launching 'mcelog')
The call chain is (as analyzed by Liu, Jinsong):
do_fork
--> copy_process
--> dup_mm
--> dup_mmap
--> copy_page_range
--> track_pfn_copy
--> reserve_pfn_range
--> line 624: flags != want_flags
It comes from different memory types of page table (_PAGE_CACHE_WB) and MTRR
(_PAGE_CACHE_UC_MINUS).
Stefan Bader dug in this deep and found out that:
"That makes it clearer as this will do
reserve_memtype(...)
--> pat_x_mtrr_type
--> mtrr_type_lookup
--> __mtrr_type_lookup
And that can return -1/0xff in case of MTRR not being enabled/initialized. Which
is not the case (given there are no messages for it in dmesg). This is not equal
to MTRR_TYPE_WRBACK and thus becomes _PAGE_CACHE_UC_MINUS.
It looks like the problem starts early in reserve_memtype:
if (!pat_enabled) {
/* This is identical to page table setting without PAT */
if (new_type) {
if (req_type == _PAGE_CACHE_WC)
*new_type = _PAGE_CACHE_UC_MINUS;
else
*new_type = req_type & _PAGE_CACHE_MASK;
}
return 0;
}
This would be what we want, that is clearing the PWT and PCD flags from the
supported flags - if pat_enabled is disabled."
This patch does that - disabling PAT.
CC: stable@vger.kernel.org # 3.3 and further
Reported-by: Sander Eikelenboom <linux@eikelenboom.it>
Reported-and-Tested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reported-and-Tested-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Pull x86/apic changes from Ingo Molnar:
"Main changes:
- Multiple MSI support added to the APIC, PCI and AHCI code - acked
by all relevant maintainers, by Alexander Gordeev.
The advantage is that multiple AHCI ports can have multiple MSI
irqs assigned, and can thus spread to multiple CPUs.
[ Drivers can make use of this new facility via the
pci_enable_msi_block_auto() method ]
- x86 IOAPIC code from interrupt remapping cleanups from Joerg
Roedel:
These patches move all interrupt remapping specific checks out of
the x86 core code and replaces the respective call-sites with
function pointers. As a result the interrupt remapping code is
better abstraced from x86 core interrupt handling code.
- Various smaller improvements, fixes and cleanups."
* 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (26 commits)
x86/intel/irq_remapping: Clean up x2apic opt-out security warning mess
x86, kvm: Fix intialization warnings in kvm.c
x86, irq: Move irq_remapped out of x86 core code
x86, io_apic: Introduce eoi_ioapic_pin call-back
x86, msi: Introduce x86_msi.compose_msi_msg call-back
x86, irq: Introduce setup_remapped_irq()
x86, irq: Move irq_remapped() check into free_remapped_irq
x86, io-apic: Remove !irq_remapped() check from __target_IO_APIC_irq()
x86, io-apic: Move CONFIG_IRQ_REMAP code out of x86 core
x86, irq: Add data structure to keep AMD specific irq remapping information
x86, irq: Move irq_remapping_enabled declaration to iommu code
x86, io_apic: Remove irq_remapping_enabled check in setup_timer_IRQ0_pin
x86, io_apic: Move irq_remapping_enabled checks out of check_timer()
x86, io_apic: Convert setup_ioapic_entry to function pointer
x86, io_apic: Introduce set_affinity function pointer
x86, msi: Use IRQ remapping specific setup_msi_irqs routine
x86, hpet: Introduce x86_msi_ops.setup_hpet_msi
x86, io_apic: Introduce x86_io_apic_ops.print_entries for debugging
x86, io_apic: Introduce x86_io_apic_ops.disable()
x86, apic: Mask IO-APIC and PIC unconditionally on LAPIC resume
...
This reverts commit 9d02b43dee.
We are doing this b/c on 32-bit PVonHVM with older hypervisors
(Xen 4.1) it ends up bothing up the start_info. This is bad b/c
we use it for the time keeping, and the timekeeping code loops
forever - as the version field never changes. Olaf says to
revert it, so lets do that.
Acked-by: Olaf Hering <olaf@aepfle.de>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
This patch updates x2apic initializaition code to allow x2apic
on VMware platform even without interrupt remapping support.
The hypervisor_x2apic_available hook was added in x2apic
initialization code and used by KVM and XEN, before this.
I have also cleaned up that code to export this hook through the
hypervisor_x86 structure.
Compile tested for KVM and XEN configs, this patch doesn't have
any functional effect on those two platforms.
On VMware platform, verified that x2apic is used in physical
mode on products that support this.
Signed-off-by: Alok N Kataria <akataria@vmware.com>
Reviewed-by: Doug Covelli <dcovelli@vmware.com>
Reviewed-by: Dan Hecht <dhecht@vmware.com>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Avi Kivity <avi@redhat.com>
Link: http://lkml.kernel.org/r/1358466282.423.60.camel@akataria-dtop.eng.vmware.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The runstate of vcpu should be restored for all possible cpus, as well as the
vcpu info placement.
Acked-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
After merging the xen-two tree, today's linux-next build (x86_64
allmodconfig) produced this warning:
arch/x86/xen/enlighten.c: In function 'init_hvm_pv_info':
arch/x86/xen/enlighten.c:1617:16: warning: unused variable 'ebx' [-Wunused-variable]
arch/x86/xen/enlighten.c:1617:11: warning: unused variable 'eax' [-Wunused-variable]
Introduced by commit 9d02b43dee ("xen PVonHVM: use E820_Reserved area
for shared_info").
Signed-off-by: Olaf Hering <olaf@aepfle.de>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
As on ia64 builds we get:
include/xen/interface/version.h: In function 'xen_running_on_version_or_later':
include/xen/interface/version.h:76: error: implicit declaration of function 'HYPERVISOR_xen_version'
We can later on make this function exportable if there are
modules using part of it. For right now the only two users are
built-in.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
With Xen acpi pad logic added into kernel, we can now revert xen mwait related
patch df88b2d96e ("xen/enlighten: Disable
MWAIT_LEAF so that acpi-pad won't be loaded. "). The reason is, when running under
newer Xen platform, Xen pad driver would be early loaded, so native pad driver
would fail to be loaded, and hence no mwait/monitor #UD risk again.
Another point is, only Xen4.2 or later support Xen acpi pad, so we won't expose
mwait cpuid capability when running under older Xen platform.
Signed-off-by: Liu, Jinsong <jinsong.liu@intel.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Juergen Gross