Arnd had sent this patch to the KVM mailing list, but it slipped through
the cracks of maintainers hand-off, and therefore wasn't included in
the pull request.
The same issue had been fixed by Linus in commit dbee3d0 ("KVM: x86:
VMX: fix build without hyper-v", 2018-06-12) as a self-described
"quick-and-hacky build fix". However, checking the compile-time
configuration symbol with IS_ENABLED is cleaner and it is enough to
avoid the link error, so switch to Arnd's solution.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
[Rewritten commit message. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Fix typo in sentence about min value calculation.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Commit ceef7d10df ("KVM: x86: VMX: hyper-v: Enlightened MSR-Bitmap
support") broke the build with Hyper-V disabled, because it accesses
ms_hyperv.nested_features without checking if that exists.
This is the quick-and-hacky build fix.
I suspect the proper fix is to replace the
static_branch_unlikely(&enable_evmcs)
tests with an inline helper function that also checks that CONFIG_HYPERV
is enabled, since without that, enable_evmcs makes no sense.
But I want a working build environment first and foremost, and I'm upset
this slipped through in the first place. My primary build tests missed
it because I tend to build with everything enabled, but it should have
been caught in the kvm tree.
Fixes: ceef7d10df ("KVM: x86: VMX: hyper-v: Enlightened MSR-Bitmap support")
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
- Additional struct_size() conversions (Matthew, Kees)
- Explicitly reported overflow fixes (Silvio, Kees)
- Add missing kvcalloc() function (Kees)
- Treewide conversions of allocators to use either 2-factor argument
variant when available, or array_size() and array3_size() as needed (Kees)
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Merge tag 'overflow-v4.18-rc1-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull more overflow updates from Kees Cook:
"The rest of the overflow changes for v4.18-rc1.
This includes the explicit overflow fixes from Silvio, further
struct_size() conversions from Matthew, and a bug fix from Dan.
But the bulk of it is the treewide conversions to use either the
2-factor argument allocators (e.g. kmalloc(a * b, ...) into
kmalloc_array(a, b, ...) or the array_size() macros (e.g. vmalloc(a *
b) into vmalloc(array_size(a, b)).
Coccinelle was fighting me on several fronts, so I've done a bunch of
manual whitespace updates in the patches as well.
Summary:
- Error path bug fix for overflow tests (Dan)
- Additional struct_size() conversions (Matthew, Kees)
- Explicitly reported overflow fixes (Silvio, Kees)
- Add missing kvcalloc() function (Kees)
- Treewide conversions of allocators to use either 2-factor argument
variant when available, or array_size() and array3_size() as needed
(Kees)"
* tag 'overflow-v4.18-rc1-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (26 commits)
treewide: Use array_size in f2fs_kvzalloc()
treewide: Use array_size() in f2fs_kzalloc()
treewide: Use array_size() in f2fs_kmalloc()
treewide: Use array_size() in sock_kmalloc()
treewide: Use array_size() in kvzalloc_node()
treewide: Use array_size() in vzalloc_node()
treewide: Use array_size() in vzalloc()
treewide: Use array_size() in vmalloc()
treewide: devm_kzalloc() -> devm_kcalloc()
treewide: devm_kmalloc() -> devm_kmalloc_array()
treewide: kvzalloc() -> kvcalloc()
treewide: kvmalloc() -> kvmalloc_array()
treewide: kzalloc_node() -> kcalloc_node()
treewide: kzalloc() -> kcalloc()
treewide: kmalloc() -> kmalloc_array()
mm: Introduce kvcalloc()
video: uvesafb: Fix integer overflow in allocation
UBIFS: Fix potential integer overflow in allocation
leds: Use struct_size() in allocation
Convert intel uncore to struct_size
...
* ARM: lazy context-switching of FPSIMD registers on arm64, "split"
regions for vGIC redistributor
* s390: cleanups for nested, clock handling, crypto, storage keys and
control register bits
* x86: many bugfixes, implement more Hyper-V super powers,
implement lapic_timer_advance_ns even when the LAPIC timer
is emulated using the processor's VMX preemption timer. Two
security-related bugfixes at the top of the branch.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM updates from Paolo Bonzini:
"Small update for KVM:
ARM:
- lazy context-switching of FPSIMD registers on arm64
- "split" regions for vGIC redistributor
s390:
- cleanups for nested
- clock handling
- crypto
- storage keys
- control register bits
x86:
- many bugfixes
- implement more Hyper-V super powers
- implement lapic_timer_advance_ns even when the LAPIC timer is
emulated using the processor's VMX preemption timer.
- two security-related bugfixes at the top of the branch"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (79 commits)
kvm: fix typo in flag name
kvm: x86: use correct privilege level for sgdt/sidt/fxsave/fxrstor access
KVM: x86: pass kvm_vcpu to kvm_read_guest_virt and kvm_write_guest_virt_system
KVM: x86: introduce linear_{read,write}_system
kvm: nVMX: Enforce cpl=0 for VMX instructions
kvm: nVMX: Add support for "VMWRITE to any supported field"
kvm: nVMX: Restrict VMX capability MSR changes
KVM: VMX: Optimize tscdeadline timer latency
KVM: docs: nVMX: Remove known limitations as they do not exist now
KVM: docs: mmu: KVM support exposing SLAT to guests
kvm: no need to check return value of debugfs_create functions
kvm: Make VM ioctl do valloc for some archs
kvm: Change return type to vm_fault_t
KVM: docs: mmu: Fix link to NPT presentation from KVM Forum 2008
kvm: x86: Amend the KVM_GET_SUPPORTED_CPUID API documentation
KVM: x86: hyperv: declare KVM_CAP_HYPERV_TLBFLUSH capability
KVM: x86: hyperv: simplistic HVCALL_FLUSH_VIRTUAL_ADDRESS_{LIST,SPACE}_EX implementation
KVM: x86: hyperv: simplistic HVCALL_FLUSH_VIRTUAL_ADDRESS_{LIST,SPACE} implementation
KVM: introduce kvm_make_vcpus_request_mask() API
KVM: x86: hyperv: do rep check for each hypercall separately
...
KVM_X86_DISABLE_EXITS_HTL really refers to exit on halt.
Obviously a typo: should be named KVM_X86_DISABLE_EXITS_HLT.
Fixes: caa057a2ca ("KVM: X86: Provide a capability to disable HLT intercepts")
Cc: stable@vger.kernel.org
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The functions that were used in the emulation of fxrstor, fxsave, sgdt and
sidt were originally meant for task switching, and as such they did not
check privilege levels. This is very bad when the same functions are used
in the emulation of unprivileged instructions. This is CVE-2018-10853.
The obvious fix is to add a new argument to ops->read_std and ops->write_std,
which decides whether the access is a "system" access or should use the
processor's CPL.
Fixes: 129a72a0d3 ("KVM: x86: Introduce segmented_write_std", 2017-01-12)
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Int the next patch the emulator's .read_std and .write_std callbacks will
grow another argument, which is not needed in kvm_read_guest_virt and
kvm_write_guest_virt_system's callers. Since we have to make separate
functions, let's give the currently existing names a nicer interface, too.
Fixes: 129a72a0d3 ("KVM: x86: Introduce segmented_write_std", 2017-01-12)
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Wrap the common invocation of ctxt->ops->read_std and ctxt->ops->write_std, so
as to have a smaller patch when the functions grow another argument.
Fixes: 129a72a0d3 ("KVM: x86: Introduce segmented_write_std", 2017-01-12)
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
VMX instructions executed inside a L1 VM will always trigger a VM exit
even when executed with cpl 3. This means we must perform the
privilege check in software.
Fixes: 70f3aac964ae("kvm: nVMX: Remove superfluous VMX instruction fault checks")
Cc: stable@vger.kernel.org
Signed-off-by: Felix Wilhelm <fwilhelm@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The AMD document outlining the SSBD handling
124441_AMD64_SpeculativeStoreBypassDisable_Whitepaper_final.pdf
mentions that if CPUID 8000_0008.EBX[24] is set we should be using
the SPEC_CTRL MSR (0x48) over the VIRT SPEC_CTRL MSR (0xC001_011f)
for speculative store bypass disable.
This in effect means we should clear the X86_FEATURE_VIRT_SSBD
flag so that we would prefer the SPEC_CTRL MSR.
See the document titled:
124441_AMD64_SpeculativeStoreBypassDisable_Whitepaper_final.pdf
A copy of this document is available at
https://bugzilla.kernel.org/show_bug.cgi?id=199889
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Janakarajan Natarajan <Janakarajan.Natarajan@amd.com>
Cc: kvm@vger.kernel.org
Cc: KarimAllah Ahmed <karahmed@amazon.de>
Cc: andrew.cooper3@citrix.com
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/20180601145921.9500-3-konrad.wilk@oracle.com
The AMD document outlining the SSBD handling
124441_AMD64_SpeculativeStoreBypassDisable_Whitepaper_final.pdf
mentions that the CPUID 8000_0008.EBX[26] will mean that the
speculative store bypass disable is no longer needed.
A copy of this document is available at:
https://bugzilla.kernel.org/show_bug.cgi?id=199889
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Janakarajan Natarajan <Janakarajan.Natarajan@amd.com>
Cc: kvm@vger.kernel.org
Cc: andrew.cooper3@citrix.com
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Link: https://lkml.kernel.org/r/20180601145921.9500-2-konrad.wilk@oracle.com
Pull siginfo updates from Eric Biederman:
"This set of changes close the known issues with setting si_code to an
invalid value, and with not fully initializing struct siginfo. There
remains work to do on nds32, arc, unicore32, powerpc, arm, arm64, ia64
and x86 to get the code that generates siginfo into a simpler and more
maintainable state. Most of that work involves refactoring the signal
handling code and thus careful code review.
Also not included is the work to shrink the in kernel version of
struct siginfo. That depends on getting the number of places that
directly manipulate struct siginfo under control, as it requires the
introduction of struct kernel_siginfo for the in kernel things.
Overall this set of changes looks like it is making good progress, and
with a little luck I will be wrapping up the siginfo work next
development cycle"
* 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (46 commits)
signal/sh: Stop gcc warning about an impossible case in do_divide_error
signal/mips: Report FPE_FLTUNK for undiagnosed floating point exceptions
signal/um: More carefully relay signals in relay_signal.
signal: Extend siginfo_layout with SIL_FAULT_{MCEERR|BNDERR|PKUERR}
signal: Remove unncessary #ifdef SEGV_PKUERR in 32bit compat code
signal/signalfd: Add support for SIGSYS
signal/signalfd: Remove __put_user from signalfd_copyinfo
signal/xtensa: Use force_sig_fault where appropriate
signal/xtensa: Consistenly use SIGBUS in do_unaligned_user
signal/um: Use force_sig_fault where appropriate
signal/sparc: Use force_sig_fault where appropriate
signal/sparc: Use send_sig_fault where appropriate
signal/sh: Use force_sig_fault where appropriate
signal/s390: Use force_sig_fault where appropriate
signal/riscv: Replace do_trap_siginfo with force_sig_fault
signal/riscv: Use force_sig_fault where appropriate
signal/parisc: Use force_sig_fault where appropriate
signal/parisc: Use force_sig_mceerr where appropriate
signal/openrisc: Use force_sig_fault where appropriate
signal/nios2: Use force_sig_fault where appropriate
...
Add support for "VMWRITE to any supported field in the VMCS" and
enable this feature by default in L1's IA32_VMX_MISC MSR. If userspace
clears the VMX capability bit, the old behavior will be restored.
Note that this feature is a prerequisite for kvm in L1 to use VMCS
shadowing, once that feature is available.
Signed-off-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Disallow changes to the VMX capability MSRs while the vCPU is in VMX
operation. Although this does break the existing API, it helps to
avoid some potentially tricky situations for which there is no
architected behavior.
Signed-off-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
'Commit d0659d946b ("KVM: x86: add option to advance tscdeadline
hrtimer expiration")' advances the tscdeadline (the timer is emulated
by hrtimer) expiration in order that the latency which is incurred
by hypervisor (apic_timer_fn -> vmentry) can be avoided. This patch
adds the advance tscdeadline expiration support to which the tscdeadline
timer is emulated by VMX preemption timer to reduce the hypervisor
lantency (handle_preemption_timer -> vmentry). The guest can also
set an expiration that is very small (for example in Linux if an
hrtimer feeds a expiration in the past); in that case we set delta_tsc
to 0, leading to an immediately vmexit when delta_tsc is not bigger than
advance ns.
This patch can reduce ~63% latency (~4450 cycles to ~1660 cycles on
a haswell desktop) for kvm-unit-tests/tscdeadline_latency when testing
busy waits.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The kvm struct has been bloating. For example, it's tens of kilo-bytes
for x86, which turns out to be a large amount of memory to allocate
contiguously via kzalloc. Thus, this patch does the following:
1. Uses architecture-specific routines to allocate the kvm struct via
vzalloc for x86.
2. Switches arm to __KVM_HAVE_ARCH_VM_ALLOC so that it can use vzalloc
when has_vhe() is true.
Other architectures continue to default to kalloc, as they have a
dependency on kalloc or have a small-enough struct kvm.
Signed-off-by: Marc Orr <marcorr@google.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Use new return type vm_fault_t for fault handler. For
now, this is just documenting that the function returns
a VM_FAULT value rather than an errno. Once all instances
are converted, vm_fault_t will become a distinct type.
commit 1c8f422059 ("mm: change return type to vm_fault_t")
Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Pull x86 store buffer fixes from Thomas Gleixner:
"Two fixes for the SSBD mitigation code:
- expose SSBD properly to guests. This got broken when the CPU
feature flags got reshuffled.
- simplify the CPU detection logic to avoid duplicate entries in the
tables"
* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/speculation: Simplify the CPU bug detection logic
KVM/VMX: Expose SSBD properly to guests
PPC:
- Close a hole which could possibly lead to the host timebase getting
out of sync.
- Three fixes relating to PTEs and TLB entries for radix guests.
- Fix a bug which could lead to an interrupt never getting delivered
to the guest, if it is pending for a guest vCPU when the vCPU gets
offlined.
s390:
- Fix false negatives in VSIE validity check (Cc stable)
x86:
- Fix time drift of VMX preemption timer when a guest uses LAPIC timer
in periodic mode (Cc stable)
- Unconditionally expose CPUID.IA32_ARCH_CAPABILITIES to allow
migration from hosts that don't need retpoline mitigation (Cc stable)
- Fix guest crashes on reboot by properly coupling CR4.OSXSAVE and
CPUID.OSXSAVE (Cc stable)
- Report correct RIP after Hyper-V hypercall #UD (introduced in -rc6)
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM fixes from Radim Krčmář:
"PPC:
- Close a hole which could possibly lead to the host timebase getting
out of sync.
- Three fixes relating to PTEs and TLB entries for radix guests.
- Fix a bug which could lead to an interrupt never getting delivered
to the guest, if it is pending for a guest vCPU when the vCPU gets
offlined.
s390:
- Fix false negatives in VSIE validity check (Cc stable)
x86:
- Fix time drift of VMX preemption timer when a guest uses LAPIC
timer in periodic mode (Cc stable)
- Unconditionally expose CPUID.IA32_ARCH_CAPABILITIES to allow
migration from hosts that don't need retpoline mitigation (Cc
stable)
- Fix guest crashes on reboot by properly coupling CR4.OSXSAVE and
CPUID.OSXSAVE (Cc stable)
- Report correct RIP after Hyper-V hypercall #UD (introduced in
-rc6)"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: x86: fix #UD address of failed Hyper-V hypercalls
kvm: x86: IA32_ARCH_CAPABILITIES is always supported
KVM: x86: Update cpuid properly when CR4.OSXAVE or CR4.PKE is changed
x86/kvm: fix LAPIC timer drift when guest uses periodic mode
KVM: s390: vsie: fix < 8k check for the itdba
KVM: PPC: Book 3S HV: Do ptesync in radix guest exit path
KVM: PPC: Book3S HV: XIVE: Resend re-routed interrupts on CPU priority change
KVM: PPC: Book3S HV: Make radix clear pte when unmapping
KVM: PPC: Book3S HV: Make radix use correct tlbie sequence in kvmppc_radix_tlbie_page
KVM: PPC: Book3S HV: Snapshot timebase offset on guest entry
We need a new capability to indicate support for the newly added
HvFlushVirtualAddress{List,Space}{,Ex} hypercalls. Upon seeing this
capability, userspace is supposed to announce PV TLB flush features
by setting the appropriate CPUID bits (if needed).
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Implement HvFlushVirtualAddress{List,Space} hypercalls in a simplistic way:
do full TLB flush with KVM_REQ_TLB_FLUSH and kick vCPUs which are currently
IN_GUEST_MODE.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Prepare to support TLB flush hypercalls, some of which are REP hypercalls.
Also, return HV_STATUS_INVALID_HYPERCALL_INPUT as it seems more
appropriate.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
If the hypercall was called from userspace or real mode, KVM injects #UD
and then advances RIP, so it looks like #UD was caused by the following
instruction. This probably won't cause more than confusion, but could
give an unexpected access to guest OS' instruction emulator.
Also, refactor the code to count hv hypercalls that were handled by the
virt userspace.
Fixes: 6356ee0c96 ("x86: Delay skip of emulated hypercall instruction")
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
The CLDEMOTE instruction hints to hardware that the cache line that
contains the linear address should be moved("demoted") from
the cache(s) closest to the processor core to a level more distant
from the processor core. This may accelerate subsequent accesses
to the line by other cores in the same coherence domain,
especially if the line was written by the core that demotes the line.
This patch exposes the cldemote feature to the guest.
The release document ref below link:
https://software.intel.com/sites/default/files/managed/c5/15/\
architecture-instruction-set-extensions-programming-reference.pdf
This patch has a dependency on https://lkml.org/lkml/2018/4/23/928
Signed-off-by: Jingqi Liu <jingqi.liu@intel.com>
Reviewed-by: Wei Wang <wei.w.wang@intel.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
When vmcs12 uses VPID, all TLB entries populated by L2 are tagged with
vmx->nested.vpid02. Currently, INVVPID executed by L1 is emulated by L0
by using INVVPID single/global-context to flush all TLB entries
tagged with vmx->nested.vpid02 regardless of INVVPID type executed by
L1.
However, we can easily optimize the case of L1 INVVPID on an
individual-address. Just INVVPID given individual-address tagged with
vmx->nested.vpid02.
Reviewed-by: Liam Merwick <liam.merwick@oracle.com>
Signed-off-by: Liran Alon <liran.alon@oracle.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
[Squashed with a preparatory patch that added the !operand.vpid line.]
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Since commit 5c614b3583 ("KVM: nVMX: nested VPID emulation"),
vmcs01 and vmcs02 don't share the same VPID. vmcs01 uses vmx->vpid
while vmcs02 uses vmx->nested.vpid02. This was done such that TLB
flush could be avoided when switching between L1 and L2.
However, the above mentioned commit only changed L2 VMEntry logic to
not flush TLB when switching from L1 to L2. It forgot to also remove
the TLB flush which is done when simulating a VMExit from L2 to L1.
To fix this issue, on VMExit from L2 to L1 we flush TLB only in case
vmcs01 enables VPID and vmcs01->vpid==vmcs02->vpid. This happens when
vmcs01 enables VPID and vmcs12 does not.
Fixes: 5c614b3583 ("KVM: nVMX: nested VPID emulation")
Reviewed-by: Liam Merwick <liam.merwick@oracle.com>
Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Signed-off-by: Liran Alon <liran.alon@oracle.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
This is a fix from reviewing the code, but it looks like it might be
able to lead to an Oops. It affects 32bit systems.
The KVM_MEMORY_ENCRYPT_REG_REGION ioctl uses a u64 for range->addr and
range->size but the high 32 bits would be truncated away on a 32 bit
system. This is harmless but it's also harmless to prevent it.
Then in sev_pin_memory() the "uaddr + ulen" calculation can wrap around.
The wrap around can happen on 32 bit or 64 bit systems, but I was only
able to figure out a problem for 32 bit systems. We would pick a number
which results in "npages" being zero. The sev_pin_memory() would then
return ZERO_SIZE_PTR without allocating anything.
I made it illegal to call sev_pin_memory() with "ulen" set to zero.
Hopefully, that doesn't cause any problems. I also changed the type of
"first" and "last" to long, just for cosmetic reasons. Otherwise on a
64 bit system you're saving "uaddr >> 12" in an int and it truncates the
high 20 bits away. The math works in the current code so far as I can
see but it's just weird.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
[Brijesh noted that the code is only reachable on X86_64.]
Reviewed-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
handle_mmio_page_fault() was recently moved to be an internal-only
MMU function, i.e. it's static and no longer defined in kvm_host.h.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
If there is a possibility that a VM may migrate to a Skylake host,
then the hypervisor should report IA32_ARCH_CAPABILITIES.RSBA[bit 2]
as being set (future work, of course). This implies that
CPUID.(EAX=7,ECX=0):EDX.ARCH_CAPABILITIES[bit 29] should be
set. Therefore, kvm should report this CPUID bit as being supported
whether or not the host supports it. Userspace is still free to clear
the bit if it chooses.
For more information on RSBA, see Intel's white paper, "Retpoline: A
Branch Target Injection Mitigation" (Document Number 337131-001),
currently available at https://bugzilla.kernel.org/show_bug.cgi?id=199511.
Since the IA32_ARCH_CAPABILITIES MSR is emulated in kvm, there is no
dependency on hardware support for this feature.
Signed-off-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Fixes: 28c1c9fabf ("KVM/VMX: Emulate MSR_IA32_ARCH_CAPABILITIES")
Cc: stable@vger.kernel.org
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
The CPUID bits of OSXSAVE (function=0x1) and OSPKE (func=0x7, leaf=0x0)
allows user apps to detect if OS has set CR4.OSXSAVE or CR4.PKE. KVM is
supposed to update these CPUID bits when CR4 is updated. Current KVM
code doesn't handle some special cases when updates come from emulator.
Here is one example:
Step 1: guest boots
Step 2: guest OS enables XSAVE ==> CR4.OSXSAVE=1 and CPUID.OSXSAVE=1
Step 3: guest hot reboot ==> QEMU reset CR4 to 0, but CPUID.OSXAVE==1
Step 4: guest os checks CPUID.OSXAVE, detects 1, then executes xgetbv
Step 4 above will cause an #UD and guest crash because guest OS hasn't
turned on OSXAVE yet. This patch solves the problem by comparing the the
old_cr4 with cr4. If the related bits have been changed,
kvm_update_cpuid() needs to be called.
Signed-off-by: Wei Huang <wei@redhat.com>
Reviewed-by: Bandan Das <bsd@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Since 4.10, commit 8003c9ae20 (KVM: LAPIC: add APIC Timer
periodic/oneshot mode VMX preemption timer support), guests using
periodic LAPIC timers (such as FreeBSD 8.4) would see their timers
drift significantly over time.
Differences in the underlying clocks and numerical errors means the
periods of the two timers (hv and sw) are not the same. This
difference will accumulate with every expiry resulting in a large
error between the hv and sw timer.
This means the sw timer may be running slow when compared to the hv
timer. When the timer is switched from hv to sw, the now active sw
timer will expire late. The guest VCPU is reentered and it switches to
using the hv timer. This timer catches up, injecting multiple IRQs
into the guest (of which the guest only sees one as it does not get to
run until the hv timer has caught up) and thus the guest's timer rate
is low (and becomes increasing slower over time as the sw timer lags
further and further behind).
I believe a similar problem would occur if the hv timer is the slower
one, but I have not observed this.
Fix this by synchronizing the deadlines for both timers to the same
time source on every tick. This prevents the errors from accumulating.
Fixes: 8003c9ae20
Cc: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: David Vrabel <david.vrabel@nutanix.com>
Cc: stable@vger.kernel.org
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Wanpeng Li <wanpengli@tencent.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Enforce the invariant that existing VMCS12 field offsets must not
change. Experience has shown that without strict enforcement, this
invariant will not be maintained.
Signed-off-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
[Changed the code to use BUILD_BUG_ON_MSG instead of better, but GCC 4.6
requiring _Static_assert. - Radim.]
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Changing the VMCS12 layout will break save/restore compatibility with
older kvm releases once the KVM_{GET,SET}_NESTED_STATE ioctls are
accepted upstream. Google has already been using these ioctls for some
time, and we implore the community not to disturb the existing layout.
Move the four most recently added fields to preserve the offsets of
the previously defined fields and reserve locations for the vmread and
vmwrite bitmaps, which will be used in the virtualization of VMCS
shadowing (to improve the performance of double-nesting).
Signed-off-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
[Kept the SDM order in vmcs_field_to_offset_table. - Radim]
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
The hypercall was added using a struct timespec based implementation,
but we should not use timespec in new code.
This changes it to timespec64. There is no functional change
here since the implementation is only used in 64-bit kernels
that use the same definition for timespec and timespec64.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
When saving a vCPU's nested state, the vmcs02 is discarded. Only the
shadow vmcs12 is saved. The shadow vmcs12 contains all of the
information needed to reconstruct an equivalent vmcs02 on restore, but
we have to be able to deal with two contexts:
1. The nested state was saved immediately after an emulated VM-entry,
before the vmcs02 was ever launched.
2. The nested state was saved some time after the first successful
launch of the vmcs02.
Though it's an implementation detail rather than an architected bit,
vmx->nested_run_pending serves to distinguish between these two
cases. Hence, we save it as part of the vCPU's nested state. (Yes,
this is ugly.)
Even when restoring from a checkpoint, it may be necessary to build
the vmcs02 as if prepare_vmcs02 was called from nested_vmx_run. So,
the 'from_vmentry' argument should be dropped, and
vmx->nested_run_pending should be consulted instead. The nested state
restoration code then has to set vmx->nested_run_pending prior to
calling prepare_vmcs02. It's important that the restoration code set
vmx->nested_run_pending anyway, since the flag impacts things like
interrupt delivery as well.
Fixes: cf8b84f48a ("kvm: nVMX: Prepare for checkpointing L2 state")
Signed-off-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
The X86_FEATURE_SSBD is an synthetic CPU feature - that is
it bit location has no relevance to the real CPUID 0x7.EBX[31]
bit position. For that we need the new CPU feature name.
Fixes: 52817587e7 ("x86/cpufeatures: Disentangle SSBD enumeration")
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: kvm@vger.kernel.org
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: stable@vger.kernel.org
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Link: https://lkml.kernel.org/r/20180521215449.26423-2-konrad.wilk@oracle.com
Merge speculative store buffer bypass fixes from Thomas Gleixner:
- rework of the SPEC_CTRL MSR management to accomodate the new fancy
SSBD (Speculative Store Bypass Disable) bit handling.
- the CPU bug and sysfs infrastructure for the exciting new Speculative
Store Bypass 'feature'.
- support for disabling SSB via LS_CFG MSR on AMD CPUs including
Hyperthread synchronization on ZEN.
- PRCTL support for dynamic runtime control of SSB
- SECCOMP integration to automatically disable SSB for sandboxed
processes with a filter flag for opt-out.
- KVM integration to allow guests fiddling with SSBD including the new
software MSR VIRT_SPEC_CTRL to handle the LS_CFG based oddities on
AMD.
- BPF protection against SSB
.. this is just the core and x86 side, other architecture support will
come separately.
* 'speck-v20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (49 commits)
bpf: Prevent memory disambiguation attack
x86/bugs: Rename SSBD_NO to SSB_NO
KVM: SVM: Implement VIRT_SPEC_CTRL support for SSBD
x86/speculation, KVM: Implement support for VIRT_SPEC_CTRL/LS_CFG
x86/bugs: Rework spec_ctrl base and mask logic
x86/bugs: Remove x86_spec_ctrl_set()
x86/bugs: Expose x86_spec_ctrl_base directly
x86/bugs: Unify x86_spec_ctrl_{set_guest,restore_host}
x86/speculation: Rework speculative_store_bypass_update()
x86/speculation: Add virtualized speculative store bypass disable support
x86/bugs, KVM: Extend speculation control for VIRT_SPEC_CTRL
x86/speculation: Handle HT correctly on AMD
x86/cpufeatures: Add FEATURE_ZEN
x86/cpufeatures: Disentangle SSBD enumeration
x86/cpufeatures: Disentangle MSR_SPEC_CTRL enumeration from IBRS
x86/speculation: Use synthetic bits for IBRS/IBPB/STIBP
KVM: SVM: Move spec control call after restore of GS
x86/cpu: Make alternative_msr_write work for 32-bit code
x86/bugs: Fix the parameters alignment and missing void
x86/bugs: Make cpu_show_common() static
...
Expose the new virtualized architectural mechanism, VIRT_SSBD, for using
speculative store bypass disable (SSBD) under SVM. This will allow guests
to use SSBD on hardware that uses non-architectural mechanisms for enabling
SSBD.
[ tglx: Folded the migration fixup from Paolo Bonzini ]
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
AMD is proposing a VIRT_SPEC_CTRL MSR to handle the Speculative Store
Bypass Disable via MSR_AMD64_LS_CFG so that guests do not have to care
about the bit position of the SSBD bit and thus facilitate migration.
Also, the sibling coordination on Family 17H CPUs can only be done on
the host.
Extend x86_spec_ctrl_set_guest() and x86_spec_ctrl_restore_host() with an
extra argument for the VIRT_SPEC_CTRL MSR.
Hand in 0 from VMX and in SVM add a new virt_spec_ctrl member to the CPU
data structure which is going to be used in later patches for the actual
implementation.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Intel and AMD have different CPUID bits hence for those use synthetic bits
which get set on the respective vendor's in init_speculation_control(). So
that debacles like what the commit message of
c65732e4f7 ("x86/cpu: Restore CPUID_8000_0008_EBX reload")
talks about don't happen anymore.
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Tested-by: Jörg Otte <jrg.otte@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Link: https://lkml.kernel.org/r/20180504161815.GG9257@pd.tnic
svm_vcpu_run() invokes x86_spec_ctrl_restore_host() after VMEXIT, but
before the host GS is restored. x86_spec_ctrl_restore_host() uses 'current'
to determine the host SSBD state of the thread. 'current' is GS based, but
host GS is not yet restored and the access causes a triple fault.
Move the call after the host GS restore.
Fixes: 885f82bfbc x86/process: Allow runtime control of Speculative Store Bypass
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Arnd Bergmann