KVM: x86: SVM: don't set VMLOAD/VMSAVE intercepts on vCPU reset

Browse source

Commit adc2a23734 ("KVM: nSVM: improve SYSENTER emulation on AMD"),
made init_vmcb set vmload/vmsave intercepts unconditionally,
and relied on svm_vcpu_after_set_cpuid to clear them when possible.

However init_vmcb is also called when the vCPU is reset, and it is
not followed by another call to svm_vcpu_after_set_cpuid because
the CPUID is already set.  This mistake makes the VMSAVE/VMLOAD intercept
to be set when it is not needed, and harms performance of the nested
guest.

Extract the relevant parts of svm_vcpu_after_set_cpuid so that they
can be called again on reset.

Fixes: adc2a23734 ("KVM: nSVM: improve SYSENTER emulation on AMD")
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

...

This commit is contained in:

Paolo Bonzini 2021-09-23 12:46:07 -04:00

parent 4c84926e22

commit 36e8194dcd

1 changed files with 34 additions and 27 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

61

arch/x86/kvm/svm/svm.c

View file