KVM: nSVM: do not change host intercepts while nested VM is running

Instead of touching the host intercepts so that the bitwise OR in
recalc_intercepts just works, mask away uninteresting intercepts
directly in recalc_intercepts.

This is cleaner and keeps the logic in one place even for intercepts
that can change even while L2 is running.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Paolo Bonzini 2020-03-04 12:57:49 -05:00
parent 727a7e27cf
commit b5ec2e020b

View file

@ -519,10 +519,24 @@ static void recalc_intercepts(struct vcpu_svm *svm)
h = &svm->nested.hsave->control;
g = &svm->nested;
c->intercept_cr = h->intercept_cr | g->intercept_cr;
c->intercept_dr = h->intercept_dr | g->intercept_dr;
c->intercept_exceptions = h->intercept_exceptions | g->intercept_exceptions;
c->intercept = h->intercept | g->intercept;
c->intercept_cr = h->intercept_cr;
c->intercept_dr = h->intercept_dr;
c->intercept_exceptions = h->intercept_exceptions;
c->intercept = h->intercept;
if (svm->vcpu.arch.hflags & HF_VINTR_MASK) {
/* We only want the cr8 intercept bits of L1 */
c->intercept_cr &= ~(1U << INTERCEPT_CR8_READ);
c->intercept_cr &= ~(1U << INTERCEPT_CR8_WRITE);
}
/* We don't want to see VMMCALLs from a nested guest */
c->intercept &= ~(1ULL << INTERCEPT_VMMCALL);
c->intercept_cr |= g->intercept_cr;
c->intercept_dr |= g->intercept_dr;
c->intercept_exceptions |= g->intercept_exceptions;
c->intercept |= g->intercept;
}
static inline struct vmcb *get_host_vmcb(struct vcpu_svm *svm)
@ -3592,15 +3606,6 @@ static void enter_svm_guest_mode(struct vcpu_svm *svm, u64 vmcb_gpa,
else
svm->vcpu.arch.hflags &= ~HF_VINTR_MASK;
if (svm->vcpu.arch.hflags & HF_VINTR_MASK) {
/* We only want the cr8 intercept bits of the guest */
clr_cr_intercept(svm, INTERCEPT_CR8_READ);
clr_cr_intercept(svm, INTERCEPT_CR8_WRITE);
}
/* We don't want to see VMMCALLs from a nested guest */
clr_intercept(svm, INTERCEPT_VMMCALL);
svm->vcpu.arch.tsc_offset += nested_vmcb->control.tsc_offset;
svm->vmcb->control.tsc_offset = svm->vcpu.arch.tsc_offset;