KVM: x86/xen: Use gfn_to_pfn_cache for vcpu_time_info
This switches the final pvclock to kvm_setup_pvclock_pfncache() and now
the old kvm_setup_pvclock_page() can be removed.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20220303154127.202856-7-dwmw2@infradead.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index d67487e..feefa1f 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3011,65 +3011,6 @@ static void kvm_setup_guest_pvclock(struct kvm_vcpu *v,
trace_kvm_pvclock_update(v->vcpu_id, &vcpu->hv_clock);
}
-static void kvm_setup_pvclock_page(struct kvm_vcpu *v,
- struct gfn_to_hva_cache *cache,
- unsigned int offset)
-{
- struct kvm_vcpu_arch *vcpu = &v->arch;
- struct pvclock_vcpu_time_info guest_hv_clock;
-
- if (unlikely(kvm_read_guest_offset_cached(v->kvm, cache,
- &guest_hv_clock, offset, sizeof(guest_hv_clock))))
- return;
-
- /* This VCPU is paused, but it's legal for a guest to read another
- * VCPU's kvmclock, so we really have to follow the specification where
- * it says that version is odd if data is being modified, and even after
- * it is consistent.
- *
- * Version field updates must be kept separate. This is because
- * kvm_write_guest_cached might use a "rep movs" instruction, and
- * writes within a string instruction are weakly ordered. So there
- * are three writes overall.
- *
- * As a small optimization, only write the version field in the first
- * and third write. The vcpu->pv_time cache is still valid, because the
- * version field is the first in the struct.
- */
- BUILD_BUG_ON(offsetof(struct pvclock_vcpu_time_info, version) != 0);
-
- if (guest_hv_clock.version & 1)
- ++guest_hv_clock.version; /* first time write, random junk */
-
- vcpu->hv_clock.version = guest_hv_clock.version + 1;
- kvm_write_guest_offset_cached(v->kvm, cache,
- &vcpu->hv_clock, offset,
- sizeof(vcpu->hv_clock.version));
-
- smp_wmb();
-
- /* retain PVCLOCK_GUEST_STOPPED if set in guest copy */
- vcpu->hv_clock.flags |= (guest_hv_clock.flags & PVCLOCK_GUEST_STOPPED);
-
- if (vcpu->pvclock_set_guest_stopped_request) {
- vcpu->hv_clock.flags |= PVCLOCK_GUEST_STOPPED;
- vcpu->pvclock_set_guest_stopped_request = false;
- }
-
- trace_kvm_pvclock_update(v->vcpu_id, &vcpu->hv_clock);
-
- kvm_write_guest_offset_cached(v->kvm, cache,
- &vcpu->hv_clock, offset,
- sizeof(vcpu->hv_clock));
-
- smp_wmb();
-
- vcpu->hv_clock.version++;
- kvm_write_guest_offset_cached(v->kvm, cache,
- &vcpu->hv_clock, offset,
- sizeof(vcpu->hv_clock.version));
-}
-
static int kvm_guest_time_update(struct kvm_vcpu *v)
{
unsigned long flags, tgt_tsc_khz;
@@ -3161,8 +3102,8 @@ static int kvm_guest_time_update(struct kvm_vcpu *v)
if (vcpu->xen.vcpu_info_cache.active)
kvm_setup_guest_pvclock(v, &vcpu->xen.vcpu_info_cache,
offsetof(struct compat_vcpu_info, time));
- if (vcpu->xen.vcpu_time_info_set)
- kvm_setup_pvclock_page(v, &vcpu->xen.vcpu_time_info_cache, 0);
+ if (vcpu->xen.vcpu_time_info_cache.active)
+ kvm_setup_guest_pvclock(v, &vcpu->xen.vcpu_time_info_cache, 0);
if (!v->vcpu_idx)
kvm_hv_setup_tsc_page(v->kvm, &vcpu->hv_clock);
return 0;
