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author | Ken Hofsass <hofsass@google.com> | 2018-01-31 16:03:36 -0800 |
---|---|---|
committer | Radim Krčmář <rkrcmar@redhat.com> | 2018-03-06 18:40:43 +0100 |
commit | 01643c51bfcf2460b530854046f62ce1b29713ab (patch) | |
tree | e7cb32f011945beac52d9bb3c373b57c41a52b6f /arch/x86/include | |
parent | 7b7e39522a61f402d41dd9a67f3fa2133ef9d4e8 (diff) | |
download | op-kernel-dev-01643c51bfcf2460b530854046f62ce1b29713ab.zip op-kernel-dev-01643c51bfcf2460b530854046f62ce1b29713ab.tar.gz |
KVM: x86: KVM_CAP_SYNC_REGS
This commit implements an enhanced x86 version of S390
KVM_CAP_SYNC_REGS functionality. KVM_CAP_SYNC_REGS "allow[s]
userspace to access certain guest registers without having
to call SET/GET_*REGS”. This reduces ioctl overhead which
is particularly important when userspace is making synchronous
guest state modifications (e.g. when emulating and/or intercepting
instructions).
Originally implemented upstream for the S390, the x86 differences
follow:
- userspace can select the register sets to be synchronized with kvm_run
using bit-flags in the kvm_valid_registers and kvm_dirty_registers
fields.
- vcpu_events is available in addition to the regs and sregs register
sets.
Signed-off-by: Ken Hofsass <hofsass@google.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
[Removed wrapper around check for reserved kvm_valid_regs. - Radim]
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Diffstat (limited to 'arch/x86/include')
-rw-r--r-- | arch/x86/include/uapi/asm/kvm.h | 19 |
1 files changed, 18 insertions, 1 deletions
diff --git a/arch/x86/include/uapi/asm/kvm.h b/arch/x86/include/uapi/asm/kvm.h index f3a9604..c535c2f 100644 --- a/arch/x86/include/uapi/asm/kvm.h +++ b/arch/x86/include/uapi/asm/kvm.h @@ -354,8 +354,25 @@ struct kvm_xcrs { __u64 padding[16]; }; -/* definition of registers in kvm_run */ +#define KVM_SYNC_X86_REGS (1UL << 0) +#define KVM_SYNC_X86_SREGS (1UL << 1) +#define KVM_SYNC_X86_EVENTS (1UL << 2) + +#define KVM_SYNC_X86_VALID_FIELDS \ + (KVM_SYNC_X86_REGS| \ + KVM_SYNC_X86_SREGS| \ + KVM_SYNC_X86_EVENTS) + +/* kvm_sync_regs struct included by kvm_run struct */ struct kvm_sync_regs { + /* Members of this structure are potentially malicious. + * Care must be taken by code reading, esp. interpreting, + * data fields from them inside KVM to prevent TOCTOU and + * double-fetch types of vulnerabilities. + */ + struct kvm_regs regs; + struct kvm_sregs sregs; + struct kvm_vcpu_events events; }; #define KVM_X86_QUIRK_LINT0_REENABLED (1 << 0) |