KVM: VMX: Add proper cache tracking for CR4

Move CR4 caching into the standard register caching mechanism in order
to take advantage of the availability checks provided by regs_avail.
This avoids multiple VMREADs and retpolines (when configured) during
nested VMX transitions as kvm_read_cr4_bits() is invoked multiple times
on each transition, e.g. when stuffing CR0 and CR3.

As an added bonus, this eliminates a kvm_x86_ops hook, saves a retpoline
on SVM when reading CR4, and squashes the confusing naming discrepancy
of "cache_reg" vs. "decache_cr4_guest_bits".

No functional change intended.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200502043234.12481-7-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Sean Christopherson
2020-05-01 21:32:30 -07:00
committed by Paolo Bonzini
parent 0cc69204e7
commit f98c1e7712
5 changed files with 14 additions and 17 deletions

View File

@@ -1525,10 +1525,6 @@ static void svm_decache_cr0_guest_bits(struct kvm_vcpu *vcpu)
{
}
static void svm_decache_cr4_guest_bits(struct kvm_vcpu *vcpu)
{
}
static void update_cr0_intercept(struct vcpu_svm *svm)
{
ulong gcr0 = svm->vcpu.arch.cr0;
@@ -4007,7 +4003,6 @@ static struct kvm_x86_ops svm_x86_ops __initdata = {
.get_cpl = svm_get_cpl,
.get_cs_db_l_bits = kvm_get_cs_db_l_bits,
.decache_cr0_guest_bits = svm_decache_cr0_guest_bits,
.decache_cr4_guest_bits = svm_decache_cr4_guest_bits,
.set_cr0 = svm_set_cr0,
.set_cr4 = svm_set_cr4,
.set_efer = svm_set_efer,