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| author | Sean Christopherson <sean.j.christopherson@intel.com> | 2020-05-01 21:32:31 -0700 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2020-05-13 12:15:12 -0400 |
| commit | bd31fe495d0d1a67fe6f44f06dfef637f202241d (patch) | |
| tree | 5bddfc09434a76ab1ccc9c02511d3949da8e6342 /arch/x86/kvm/kvm_cache_regs.h | |
| parent | f98c1e77127de7d9ff558570c25d02ef077df50f (diff) | |
| download | lwn-bd31fe495d0d1a67fe6f44f06dfef637f202241d.tar.gz lwn-bd31fe495d0d1a67fe6f44f06dfef637f202241d.zip | |
KVM: VMX: Add proper cache tracking for CR0
Move CR0 caching into the standard register caching mechanism in order
to take advantage of the availability checks provided by regs_avail.
This avoids multiple VMREADs in the (uncommon) case where kvm_read_cr0()
is called multiple times in a single VM-Exit, and more importantly
eliminates a kvm_x86_ops hook, saves a retpoline on SVM when reading
CR0, and squashes the confusing naming discrepancy of "cache_reg" vs.
"decache_cr0_guest_bits".
No functional change intended.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200502043234.12481-8-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/kvm_cache_regs.h')
| -rw-r--r-- | arch/x86/kvm/kvm_cache_regs.h | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/arch/x86/kvm/kvm_cache_regs.h b/arch/x86/kvm/kvm_cache_regs.h index 921a539bcb96..ff2d0e9ca3bc 100644 --- a/arch/x86/kvm/kvm_cache_regs.h +++ b/arch/x86/kvm/kvm_cache_regs.h @@ -116,8 +116,9 @@ static inline u64 kvm_pdptr_read(struct kvm_vcpu *vcpu, int index) static inline ulong kvm_read_cr0_bits(struct kvm_vcpu *vcpu, ulong mask) { ulong tmask = mask & KVM_POSSIBLE_CR0_GUEST_BITS; - if (tmask & vcpu->arch.cr0_guest_owned_bits) - kvm_x86_ops.decache_cr0_guest_bits(vcpu); + if ((tmask & vcpu->arch.cr0_guest_owned_bits) && + !kvm_register_is_available(vcpu, VCPU_EXREG_CR0)) + kvm_x86_ops.cache_reg(vcpu, VCPU_EXREG_CR0); return vcpu->arch.cr0 & mask; } |