In order to interoperate correctly with the rest of KVM and other Linux
subsystems, the TDP MMU must correctly handle various MMU notifiers. Add
a hook and handle the change_pte MMU notifier.
Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell
machine. This series introduced no new failures.
This series can be viewed in Gerrit at:
https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538
Signed-off-by: Ben Gardon <bgardon@google.com>
Message-Id: <20201014182700.2888246-15-bgardon@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
In order to interoperate correctly with the rest of KVM and other Linux
subsystems, the TDP MMU must correctly handle various MMU notifiers. The
main Linux MM uses the access tracking MMU notifiers for swap and other
features. Add hooks to handle the test/flush HVA (range) family of
MMU notifiers.
Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell
machine. This series introduced no new failures.
This series can be viewed in Gerrit at:
https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538
Signed-off-by: Ben Gardon <bgardon@google.com>
Message-Id: <20201014182700.2888246-14-bgardon@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
In order to interoperate correctly with the rest of KVM and other Linux
subsystems, the TDP MMU must correctly handle various MMU notifiers. Add
hooks to handle the invalidate range family of MMU notifiers.
Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell
machine. This series introduced no new failures.
This series can be viewed in Gerrit at:
https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538
Signed-off-by: Ben Gardon <bgardon@google.com>
Message-Id: <20201014182700.2888246-13-bgardon@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add functions to handle page faults in the TDP MMU. These page faults
are currently handled in much the same way as the x86 shadow paging
based MMU, however the ordering of some operations is slightly
different. Future patches will add eager NX splitting, a fast page fault
handler, and parallel page faults.
Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell
machine. This series introduced no new failures.
This series can be viewed in Gerrit at:
https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538
Signed-off-by: Ben Gardon <bgardon@google.com>
Message-Id: <20201014182700.2888246-11-bgardon@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The HP 730 machine returned strange errors when I tried setting the rtc
time. Add some debug code to improve the possibility to trace errors
and document that hppa probably has as Y2k38 problem.
Signed-off-by: Helge Deller <deller@gmx.de>
Pull Kbuild updates from Masahiro Yamada:
- Support 'make compile_commands.json' to generate the compilation
database more easily, avoiding stale entries
- Support 'make clang-analyzer' and 'make clang-tidy' for static checks
using clang-tidy
- Preprocess scripts/modules.lds.S to allow CONFIG options in the
module linker script
- Drop cc-option tests from compiler flags supported by our minimal
GCC/Clang versions
- Use always 12-digits commit hash for CONFIG_LOCALVERSION_AUTO=y
- Use sha1 build id for both BFD linker and LLD
- Improve deb-pkg for reproducible builds and rootless builds
- Remove stale, useless scripts/namespace.pl
- Turn -Wreturn-type warning into error
- Fix build error of deb-pkg when CONFIG_MODULES=n
- Replace 'hostname' command with more portable 'uname -n'
- Various Makefile cleanups
* tag 'kbuild-v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (34 commits)
kbuild: Use uname for LINUX_COMPILE_HOST detection
kbuild: Only add -fno-var-tracking-assignments for old GCC versions
kbuild: remove leftover comment for filechk utility
treewide: remove DISABLE_LTO
kbuild: deb-pkg: clean up package name variables
kbuild: deb-pkg: do not build linux-headers package if CONFIG_MODULES=n
kbuild: enforce -Werror=return-type
scripts: remove namespace.pl
builddeb: Add support for all required debian/rules targets
builddeb: Enable rootless builds
builddeb: Pass -n to gzip for reproducible packages
kbuild: split the build log of kallsyms
kbuild: explicitly specify the build id style
scripts/setlocalversion: make git describe output more reliable
kbuild: remove cc-option test of -Werror=date-time
kbuild: remove cc-option test of -fno-stack-check
kbuild: remove cc-option test of -fno-strict-overflow
kbuild: move CFLAGS_{KASAN,UBSAN,KCSAN} exports to relevant Makefiles
kbuild: remove redundant CONFIG_KASAN check from scripts/Makefile.kasan
kbuild: do not create built-in objects for external module builds
...
Pull VFIO updates from Alex Williamson:
- New fsl-mc vfio bus driver supporting userspace drivers of objects
within NXP's DPAA2 architecture (Diana Craciun)
- Support for exposing zPCI information on s390 (Matthew Rosato)
- Fixes for "detached" VFs on s390 (Matthew Rosato)
- Fixes for pin-pages and dma-rw accesses (Yan Zhao)
- Cleanups and optimize vconfig regen (Zenghui Yu)
- Fix duplicate irq-bypass token registration (Alex Williamson)
* tag 'vfio-v5.10-rc1' of git://github.com/awilliam/linux-vfio: (30 commits)
vfio iommu type1: Fix memory leak in vfio_iommu_type1_pin_pages
vfio/pci: Clear token on bypass registration failure
vfio/fsl-mc: fix the return of the uninitialized variable ret
vfio/fsl-mc: Fix the dead code in vfio_fsl_mc_set_irq_trigger
vfio/fsl-mc: Fixed vfio-fsl-mc driver compilation on 32 bit
MAINTAINERS: Add entry for s390 vfio-pci
vfio-pci/zdev: Add zPCI capabilities to VFIO_DEVICE_GET_INFO
vfio/fsl-mc: Add support for device reset
vfio/fsl-mc: Add read/write support for fsl-mc devices
vfio/fsl-mc: trigger an interrupt via eventfd
vfio/fsl-mc: Add irq infrastructure for fsl-mc devices
vfio/fsl-mc: Added lock support in preparation for interrupt handling
vfio/fsl-mc: Allow userspace to MMAP fsl-mc device MMIO regions
vfio/fsl-mc: Implement VFIO_DEVICE_GET_REGION_INFO ioctl call
vfio/fsl-mc: Implement VFIO_DEVICE_GET_INFO ioctl
vfio/fsl-mc: Scan DPRC objects on vfio-fsl-mc driver bind
vfio: Introduce capability definitions for VFIO_DEVICE_GET_INFO
s390/pci: track whether util_str is valid in the zpci_dev
s390/pci: stash version in the zpci_dev
vfio/fsl-mc: Add VFIO framework skeleton for fsl-mc devices
...
commit feb92d7d38 "(ARC: perf: don't bail setup if pct irq
missing in device-tree)" introduced a silly brown-paper bag bug:
The assignment and comparison in an if statement were not bracketed
correctly leaving the order of evaluation undefined.
|
| if (has_interrupts && (irq = platform_get_irq(pdev, 0) >= 0)) {
| ^^^ ^^^^
And given such a chance, the compiler will bite you hard, fully entitled
to generating this piece of beauty:
|
| # if (has_interrupts && (irq = platform_get_irq(pdev, 0) >= 0)) {
|
| bl.d @platform_get_irq <-- irq returned in r0
|
| setge r2, r0, 0 <-- r2 is bool 1 or 0 if irq >= 0 true/false
| brlt.d r0, 0, @.L114
|
| st_s r2,[sp] <-- irq saved is bool 1 or 0, not actual return val
| st 1,[r3,160] # arc_pmu.18_29->irq <-- drops bool and assumes 1
|
| # return __request_percpu_irq(irq, handler, 0,
|
| bl.d @__request_percpu_irq;
| mov_s r0,1 <-- drops even bool and assumes 1 which fails
With the snafu fixed, everything is as expected.
| bl.d @platform_get_irq <-- returns irq in r0
|
| mov_s r2,r0
| brlt.d r2, 0, @.L112
|
| st_s r0,[sp] <-- irq isaved is actual return value above
| st r0,[r13,160] #arc_pmu.18_27->irq
|
| bl.d @__request_percpu_irq <-- r0 unchanged so actual irq returned
| add r4,r4,r12 #, tmp363, __ptr
Cc: <stable@vger.kernel.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Pull initial set_fs() removal from Al Viro:
"Christoph's set_fs base series + fixups"
* 'work.set_fs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
fs: Allow a NULL pos pointer to __kernel_read
fs: Allow a NULL pos pointer to __kernel_write
powerpc: remove address space overrides using set_fs()
powerpc: use non-set_fs based maccess routines
x86: remove address space overrides using set_fs()
x86: make TASK_SIZE_MAX usable from assembly code
x86: move PAGE_OFFSET, TASK_SIZE & friends to page_{32,64}_types.h
lkdtm: remove set_fs-based tests
test_bitmap: remove user bitmap tests
uaccess: add infrastructure for kernel builds with set_fs()
fs: don't allow splice read/write without explicit ops
fs: don't allow kernel reads and writes without iter ops
sysctl: Convert to iter interfaces
proc: add a read_iter method to proc proc_ops
proc: cleanup the compat vs no compat file ops
proc: remove a level of indentation in proc_get_inode
When an UE or memory error exception is encountered the MCE handler
tries to find the pfn using addr_to_pfn() which takes effective
address as an argument, later pfn is used to poison the page where
memory error occurred, recent rework in this area made addr_to_pfn
to run in real mode, which can be fatal as it may try to access
memory outside RMO region.
Have two helper functions to separate things to be done in real mode
and virtual mode without changing any functionality. This also fixes
the following error as the use of addr_to_pfn is now moved to virtual
mode.
Without this change following kernel crash is seen on hitting UE.
[ 485.128036] Oops: Kernel access of bad area, sig: 11 [#1]
[ 485.128040] LE SMP NR_CPUS=2048 NUMA pSeries
[ 485.128047] Modules linked in:
[ 485.128067] CPU: 15 PID: 6536 Comm: insmod Kdump: loaded Tainted: G OE 5.7.0 #22
[ 485.128074] NIP: c00000000009b24c LR: c0000000000398d8 CTR: c000000000cd57c0
[ 485.128078] REGS: c000000003f1f970 TRAP: 0300 Tainted: G OE (5.7.0)
[ 485.128082] MSR: 8000000000001003 <SF,ME,RI,LE> CR: 28008284 XER: 00000001
[ 485.128088] CFAR: c00000000009b190 DAR: c0000001fab00000 DSISR: 40000000 IRQMASK: 1
[ 485.128088] GPR00: 0000000000000001 c000000003f1fbf0 c000000001634300 0000b0fa01000000
[ 485.128088] GPR04: d000000002220000 0000000000000000 00000000fab00000 0000000000000022
[ 485.128088] GPR08: c0000001fab00000 0000000000000000 c0000001fab00000 c000000003f1fc14
[ 485.128088] GPR12: 0000000000000008 c000000003ff5880 d000000002100008 0000000000000000
[ 485.128088] GPR16: 000000000000ff20 000000000000fff1 000000000000fff2 d0000000021a1100
[ 485.128088] GPR20: d000000002200000 c00000015c893c50 c000000000d49b28 c00000015c893c50
[ 485.128088] GPR24: d0000000021a0d08 c0000000014e5da8 d0000000021a0818 000000000000000a
[ 485.128088] GPR28: 0000000000000008 000000000000000a c0000000017e2970 000000000000000a
[ 485.128125] NIP [c00000000009b24c] __find_linux_pte+0x11c/0x310
[ 485.128130] LR [c0000000000398d8] addr_to_pfn+0x138/0x170
[ 485.128133] Call Trace:
[ 485.128135] Instruction dump:
[ 485.128138] 3929ffff 7d4a3378 7c883c36 7d2907b4 794a1564 7d294038 794af082 3900ffff
[ 485.128144] 79291f24 790af00e 78e70020 7d095214 <7c69502a> 2fa30000 419e011c 70690040
[ 485.128152] ---[ end trace d34b27e29ae0e340 ]---
Fixes: 9ca766f989 ("powerpc/64s/pseries: machine check convert to use common event code")
Signed-off-by: Ganesh Goudar <ganeshgr@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200724063946.21378-1-ganeshgr@linux.ibm.com
GCC 4.9 sometimes fails to build with "m<>" constraint in
inline assembly.
CC lib/iov_iter.o
In file included from ./arch/powerpc/include/asm/cmpxchg.h:6:0,
from ./arch/powerpc/include/asm/atomic.h:11,
from ./include/linux/atomic.h:7,
from ./include/linux/crypto.h:15,
from ./include/crypto/hash.h:11,
from lib/iov_iter.c:2:
lib/iov_iter.c: In function 'iovec_from_user.part.30':
./arch/powerpc/include/asm/uaccess.h:287:2: error: 'asm' operand has impossible constraints
__asm__ __volatile__( \
^
./include/linux/compiler.h:78:42: note: in definition of macro 'unlikely'
# define unlikely(x) __builtin_expect(!!(x), 0)
^
./arch/powerpc/include/asm/uaccess.h:583:34: note: in expansion of macro 'unsafe_op_wrap'
#define unsafe_get_user(x, p, e) unsafe_op_wrap(__get_user_allowed(x, p), e)
^
./arch/powerpc/include/asm/uaccess.h:329:10: note: in expansion of macro '__get_user_asm'
case 4: __get_user_asm(x, (u32 __user *)ptr, retval, "lwz"); break; \
^
./arch/powerpc/include/asm/uaccess.h:363:3: note: in expansion of macro '__get_user_size_allowed'
__get_user_size_allowed(__gu_val, __gu_addr, __gu_size, __gu_err); \
^
./arch/powerpc/include/asm/uaccess.h💯2: note: in expansion of macro '__get_user_nocheck'
__get_user_nocheck((x), (ptr), sizeof(*(ptr)), false)
^
./arch/powerpc/include/asm/uaccess.h:583:49: note: in expansion of macro '__get_user_allowed'
#define unsafe_get_user(x, p, e) unsafe_op_wrap(__get_user_allowed(x, p), e)
^
lib/iov_iter.c:1663:3: note: in expansion of macro 'unsafe_get_user'
unsafe_get_user(len, &uiov[i].iov_len, uaccess_end);
^
make[1]: *** [scripts/Makefile.build:283: lib/iov_iter.o] Error 1
Define a UPD_CONSTR macro that is "<>" by default and
only "" with GCC prior to GCC 5.
Fixes: fcf1f26895 ("powerpc/uaccess: Add pre-update addressing to __put_user_asm_goto()")
Fixes: 2f279eeb68 ("powerpc/uaccess: Add pre-update addressing to __get_user_asm() and __put_user_asm()")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Segher Boessenkool <segher@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/212d3bc4a52ca71523759517bb9c61f7e477c46a.1603179582.git.christophe.leroy@csgroup.eu
In commit 269e583357 ("powerpc/eeh: Delete eeh_pe->config_addr") the
following simplification was made:
- if (!pe->addr && !pe->config_addr) {
+ if (!pe->addr) {
eeh_stats.no_cfg_addr++;
return 0;
}
This introduced a bug which causes EEH checking to be skipped for
devices in PE#0.
Before the change above the check would always pass since at least one
of the two PE addresses would be non-zero in all circumstances. On
PowerNV pe->config_addr would be the BDFN of the first device added to
the PE. The zero BDFN is reserved for the PHB's root port, but this is
fine since for obscure platform reasons the root port is never
assigned to PE#0.
Similarly, on pseries pe->addr has always been non-zero for the
reasons outlined in commit 42de19d5ef ("powerpc/pseries/eeh: Allow
zero to be a valid PE configuration address").
We can fix the problem by deleting the block entirely The original
purpose of this test was to avoid performing EEH checks on devices
that were not on an EEH capable bus. In modern Linux the edev->pe
pointer will be NULL for devices that are not on an EEH capable bus.
The code block immediately above this one already checks for the
edev->pe == NULL case so this test (new and old) is entirely
redundant.
Ideally we'd delete eeh_stats.no_cfg_addr too since nothing increments
it any more. Unfortunately, that information is exposed via
/proc/powerpc/eeh which means it's technically ABI. We could make it
hard-coded, but that's a change for another patch.
Fixes: 269e583357 ("powerpc/eeh: Delete eeh_pe->config_addr")
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201021232554.1434687-1-oohall@gmail.com
In order to avoid creating executable hugepages in the TDP MMU PF
handler, remove the dependency between disallowed_hugepage_adjust and
the shadow_walk_iterator. This will open the function up to being used
by the TDP MMU PF handler in a future patch.
Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell
machine. This series introduced no new failures.
This series can be viewed in Gerrit at:
https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538
Signed-off-by: Ben Gardon <bgardon@google.com>
Message-Id: <20201014182700.2888246-10-bgardon@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add functions to zap SPTEs to the TDP MMU. These are needed to tear down
TDP MMU roots properly and implement other MMU functions which require
tearing down mappings. Future patches will add functions to populate the
page tables, but as for this patch there will not be any work for these
functions to do.
Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell
machine. This series introduced no new failures.
This series can be viewed in Gerrit at:
https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538
Signed-off-by: Ben Gardon <bgardon@google.com>
Message-Id: <20201014182700.2888246-8-bgardon@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The existing bookkeeping done by KVM when a PTE is changed is spread
around several functions. This makes it difficult to remember all the
stats, bitmaps, and other subsystems that need to be updated whenever a
PTE is modified. When a non-leaf PTE is marked non-present or becomes a
leaf PTE, page table memory must also be freed. To simplify the MMU and
facilitate the use of atomic operations on SPTEs in future patches, create
functions to handle some of the bookkeeping required as a result of
a change.
Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell
machine. This series introduced no new failures.
This series can be viewed in Gerrit at:
https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538
Signed-off-by: Ben Gardon <bgardon@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The TDP MMU must be able to allocate paging structure root pages and track
the usage of those pages. Implement a similar, but separate system for root
page allocation to that of the x86 shadow paging implementation. When
future patches add synchronization model changes to allow for parallel
page faults, these pages will need to be handled differently from the
x86 shadow paging based MMU's root pages.
Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell
machine. This series introduced no new failures.
This series can be viewed in Gerrit at:
https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538
Signed-off-by: Ben Gardon <bgardon@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The TDP MMU offers an alternative mode of operation to the x86 shadow
paging based MMU, optimized for running an L1 guest with TDP. The TDP MMU
will require new fields that need to be initialized and torn down. Add
hooks into the existing KVM MMU initialization process to do that
initialization / cleanup. Currently the initialization and cleanup
fucntions do not do very much, however more operations will be added in
future patches.
Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell
machine. This series introduced no new failures.
This series can be viewed in Gerrit at:
https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538
Signed-off-by: Ben Gardon <bgardon@google.com>
Message-Id: <20201014182700.2888246-4-bgardon@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The TDP iterator implements a pre-order traversal of a TDP paging
structure. This iterator will be used in future patches to create
an efficient implementation of the KVM MMU for the TDP case.
Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell
machine. This series introduced no new failures.
This series can be viewed in Gerrit at:
https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538
Signed-off-by: Ben Gardon <bgardon@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The SPTE format will be common to both the shadow and the TDP MMU.
Extract code that implements the format to a separate module, as a
first step towards adding the TDP MMU and putting mmu.c on a diet.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The TDP MMU's own function for the changed-PTE notifier will need to be
update a PTE in the exact same way as the shadow MMU. Rather than
re-implementing this logic, factor the SPTE creation out of kvm_set_pte_rmapp.
Extracted out of a patch by Ben Gardon. <bgardon@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Separate the functions for generating leaf page table entries from the
function that inserts them into the paging structure. This refactoring
will facilitate changes to the MMU sychronization model to use atomic
compare / exchanges (which are not guaranteed to succeed) instead of a
monolithic MMU lock.
No functional change expected.
Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell
machine. This commit introduced no new failures.
This series can be viewed in Gerrit at:
https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538
Signed-off-by: Ben Gardon <bgardon@google.com>
Reviewed-by: Peter Shier <pshier@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The TDP MMU page fault handler will need to be able to create non-leaf
SPTEs to build up the paging structures. Rather than re-implementing the
function, factor the SPTE creation out of link_shadow_page.
Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell
machine. This series introduced no new failures.
This series can be viewed in Gerrit at:
https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538
Signed-off-by: Ben Gardon <bgardon@google.com>
Message-Id: <20200925212302.3979661-9-bgardon@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add FSGSBASE to the set of possible guest-owned CR4 bits, i.e. let the
guest own it on VMX. KVM never queries the guest's CR4.FSGSBASE value,
thus there is no reason to force VM-Exit on FSGSBASE being toggled.
Note, because FSGSBASE is conditionally available, this is dependent on
recent changes to intercept reserved CR4 bits and to update the CR4
guest/host mask in response to guest CPUID changes.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
[sean: added justification in changelog]
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200930041659.28181-6-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Intercept CR4 bits that are guest reserved so that KVM correctly injects
a #GP fault if the guest attempts to set a reserved bit. If a feature
is supported by the CPU but is not exposed to the guest, and its
associated CR4 bit is not intercepted by KVM by default, then KVM will
fail to inject a #GP if the guest sets the CR4 bit without triggering
an exit, e.g. by toggling only the bit in question.
Note, KVM doesn't give the guest direct access to any CR4 bits that are
also dependent on guest CPUID. Yet.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200930041659.28181-5-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Now that vcpu_after_set_cpuid() and update_exception_bitmap() are called
back-to-back, subsume the exception bitmap update into the common CPUID
update. Drop the SVM invocation entirely as SVM's exception bitmap
doesn't vary with respect to guest CPUID.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200930041659.28181-4-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Move the call to kvm_x86_ops.vcpu_after_set_cpuid() to the very end of
kvm_vcpu_after_set_cpuid() to allow the vendor implementation to react
to changes made by the common code. In the near future, this will be
used by VMX to update its CR4 guest/host masks to account for reserved
bits. In the long term, SGX support will update the allowed XCR0 mask
for enclaves based on the vCPU's allowed XCR0.
vcpu_after_set_cpuid() (nee kvm_update_cpuid()) was originally added by
commit 2acf923e38 ("KVM: VMX: Enable XSAVE/XRSTOR for guest"), and was
called separately after kvm_x86_ops.vcpu_after_set_cpuid() (nee
kvm_x86_ops->cpuid_update()). There is no indication that the placement
of the common code updates after the vendor updates was anything more
than a "new function at the end" decision.
Inspection of the current code reveals no dependency on kvm_x86_ops'
vcpu_after_set_cpuid() in kvm_vcpu_after_set_cpuid() or any of its
helpers. The bulk of the common code depends only on the guest's CPUID
configuration, kvm_mmu_reset_context() does not consume dynamic vendor
state, and there are no collisions between kvm_pmu_refresh() and VMX's
update of PT state.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200930041659.28181-3-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Unconditionally intercept changes to CR4.LA57 so that KVM correctly
injects a #GP fault if the guest attempts to set CR4.LA57 when it's
supported in hardware but not exposed to the guest.
Long term, KVM needs to properly handle CR4 bits that can be under guest
control but also may be reserved from the guest's perspective. But, KVM
currently sets the CR4 guest/host mask only during vCPU creation, and
reworking flows to change that will take a bit of elbow grease.
Even if/when generic support for intercepting reserved bits exists, it's
probably not worth letting the guest set CR4.LA57 directly. LA57 can't
be toggled while long mode is enabled, thus it's all but guaranteed to
be set once (maybe twice, e.g. by BIOS and kernel) during boot and never
touched again. On the flip side, letting the guest own CR4.LA57 may
incur extra VMREADs. In other words, this temporary "hack" is probably
also the right long term fix.
Fixes: fd8cb43373 ("KVM: MMU: Expose the LA57 feature to VM.")
Cc: stable@vger.kernel.org
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
[sean: rewrote changelog]
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200930041659.28181-2-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The function amd_ir_set_vcpu_affinity makes use of the parameter struct
amd_iommu_pi_data.prev_ga_tag to determine if it should delete struct
amd_iommu_pi_data from a list when not running in AVIC mode.
However, prev_ga_tag is initialized only when AVIC is enabled. The non-zero
uninitialized value can cause unintended code path, which ends up making
use of the struct vcpu_svm.ir_list and ir_list_lock without being
initialized (since they are intended only for the AVIC case).
This triggers NULL pointer dereference bug in the function vm_ir_list_del
with the following call trace:
svm_update_pi_irte+0x3c2/0x550 [kvm_amd]
? proc_create_single_data+0x41/0x50
kvm_arch_irq_bypass_add_producer+0x40/0x60 [kvm]
__connect+0x5f/0xb0 [irqbypass]
irq_bypass_register_producer+0xf8/0x120 [irqbypass]
vfio_msi_set_vector_signal+0x1de/0x2d0 [vfio_pci]
vfio_msi_set_block+0x77/0xe0 [vfio_pci]
vfio_pci_set_msi_trigger+0x25c/0x2f0 [vfio_pci]
vfio_pci_set_irqs_ioctl+0x88/0xb0 [vfio_pci]
vfio_pci_ioctl+0x2ea/0xed0 [vfio_pci]
? alloc_file_pseudo+0xa5/0x100
vfio_device_fops_unl_ioctl+0x26/0x30 [vfio]
? vfio_device_fops_unl_ioctl+0x26/0x30 [vfio]
__x64_sys_ioctl+0x96/0xd0
do_syscall_64+0x37/0x80
entry_SYSCALL_64_after_hwframe+0x44/0xa9
Therefore, initialize prev_ga_tag to zero before use. This should be safe
because ga_tag value 0 is invalid (see function avic_vm_init).
Fixes: dfa20099e2 ("KVM: SVM: Refactor AVIC vcpu initialization into avic_init_vcpu()")
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Message-Id: <20201003232707.4662-1-suravee.suthikulpanit@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Return 1 on errors that are caused by wrong guest behavior
(which will inject #GP to the guest)
And return a negative error value on issues that are
the kernel's fault (e.g -ENOMEM)
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20201001112954.6258-2-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
As vcpu->arch.cpuid_entries is now allocated dynamically, the only
remaining use for KVM_MAX_CPUID_ENTRIES is to check KVM_SET_CPUID/
KVM_SET_CPUID2 input for sanity. Since it was reported that the
current limit (80) is insufficient for some CPUs, bump
KVM_MAX_CPUID_ENTRIES and use an arbitrary value '256' as the new
limit.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20201001130541.1398392-4-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The current limit for guest CPUID leaves (KVM_MAX_CPUID_ENTRIES, 80)
is reported to be insufficient but before we bump it let's switch to
allocating vcpu->arch.cpuid_entries[] array dynamically. Currently,
'struct kvm_cpuid_entry2' is 40 bytes so vcpu->arch.cpuid_entries is
3200 bytes which accounts for 1/4 of the whole 'struct kvm_vcpu_arch'
but having it pre-allocated (for all vCPUs which we also pre-allocate)
gives us no real benefits.
Another plus of the dynamic allocation is that we now do kvm_check_cpuid()
check before we assign anything to vcpu->arch.cpuid_nent/cpuid_entries so
no changes are made in case the check fails.
Opportunistically remove unneeded 'out' labels from
kvm_vcpu_ioctl_set_cpuid()/kvm_vcpu_ioctl_set_cpuid2() and return
directly whenever possible.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20201001130541.1398392-3-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
As a preparatory step to allocating vcpu->arch.cpuid_entries dynamically
make kvm_check_cpuid() check work with an arbitrary 'struct kvm_cpuid_entry2'
array.
Currently, when kvm_check_cpuid() fails we reset vcpu->arch.cpuid_nent to
0 and this is kind of weird, i.e. one would expect CPUIDs to remain
unchanged when KVM_SET_CPUID[2] call fails.
No functional change intended. It would've been possible to move the updated
kvm_check_cpuid() in kvm_vcpu_ioctl_set_cpuid2() and check the supplied
input before we start updating vcpu->arch.cpuid_entries/nent but we
can't do the same in kvm_vcpu_ioctl_set_cpuid() as we'll have to copy
'struct kvm_cpuid_entry' entries first. The change will be made when
vcpu->arch.cpuid_entries[] array becomes allocated dynamically.
Suggested-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20201001130541.1398392-2-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM unconditionally provides PV features to the guest, regardless of the
configured CPUID. An unwitting guest that doesn't check
KVM_CPUID_FEATURES before use could access paravirt features that
userspace did not intend to provide. Fix this by checking the guest's
CPUID before performing any paravirtual operations.
Introduce a capability, KVM_CAP_ENFORCE_PV_FEATURE_CPUID, to gate the
aforementioned enforcement. Migrating a VM from a host w/o this patch to
a host with this patch could silently change the ABI exposed to the
guest, warranting that we default to the old behavior and opt-in for
the new one.
Reviewed-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Peter Shier <pshier@google.com>
Signed-off-by: Oliver Upton <oupton@google.com>
Change-Id: I202a0926f65035b872bfe8ad15307c026de59a98
Message-Id: <20200818152429.1923996-4-oupton@google.com>
Reviewed-by: Wanpeng Li <wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM was switched to interrupt-based mechanism for 'page ready' event
delivery in Linux-5.8 (see commit 2635b5c4a0 ("KVM: x86: interrupt based
APF 'page ready' event delivery")) and #PF (ab)use for 'page ready' event
delivery was removed. Linux guest switched to this new mechanism
exclusively in 5.9 (see commit b1d405751c ("KVM: x86: Switch KVM guest to
using interrupts for page ready APF delivery")) so it is not possible to
get #PF for a 'page ready' event even when the guest is running on top
of an older KVM (APF mechanism won't be enabled). Update the comment in
exc_page_fault() to reflect the new reality.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20201002154313.1505327-1-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Allowing userspace to intercept reads to x2APIC MSRs when APICV is
fully enabled for the guest simply can't work. But more in general,
the LAPIC could be set to in-kernel after the MSR filter is setup
and allowing accesses by userspace would be very confusing.
We could in principle allow userspace to intercept reads and writes to TPR,
and writes to EOI and SELF_IPI, but while that could be made it work, it
would still be silly.
Cc: Alexander Graf <graf@amazon.com>
Cc: Aaron Lewis <aaronlewis@google.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Rework the resetting of the MSR bitmap for x2APIC MSRs to ignore userspace
filtering. Allowing userspace to intercept reads to x2APIC MSRs when
APICV is fully enabled for the guest simply can't work; the LAPIC and thus
virtual APIC is in-kernel and cannot be directly accessed by userspace.
To keep things simple we will in fact forbid intercepting x2APIC MSRs
altogether, independent of the default_allow setting.
Cc: Alexander Graf <graf@amazon.com>
Cc: Aaron Lewis <aaronlewis@google.com>
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20201005195532.8674-3-sean.j.christopherson@intel.com>
[Modified to operate even if APICv is disabled, adjust documentation. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
- Remove unnecessary #includes (Gustavo Pimentel)
- Fix intel_mid_pci.c build error when !CONFIG_ACPI (Randy Dunlap)
- Use scnprintf(), not snprintf(), in sysfs "show" functions (Krzysztof
Wilczyński)
- Simplify pci-pf-stub by using module_pci_driver() (Liu Shixin)
- Print IRQ used by Link Bandwidth Notification (Dongdong Liu)
- Update sysfs mmap-related #ifdef comments (Clint Sbisa)
- Simplify pci_dev_reset_slot_function() (Lukas Wunner)
- Use "NULL" instead of "0" to fix sparse warnings (Gustavo Pimentel)
- Simplify bool comparisons (Krzysztof Wilczyński)
- Drop double zeroing for P2PDMA sg_init_table() (Julia Lawall)
* pci/misc:
PCI: v3-semi: Remove unneeded break
PCI/P2PDMA: Drop double zeroing for sg_init_table()
PCI: Simplify bool comparisons
PCI: endpoint: Use "NULL" instead of "0" as a NULL pointer
PCI: Simplify pci_dev_reset_slot_function()
PCI: Update mmap-related #ifdef comments
PCI/LINK: Print IRQ number used by port
PCI/IOV: Simplify pci-pf-stub with module_pci_driver()
PCI: Use scnprintf(), not snprintf(), in sysfs "show" functions
x86/PCI: Fix intel_mid_pci.c build error when ACPI is not enabled
PCI: Remove unnecessary header includes
