[v4,11/16] KVM: x86/xen: setup pvclock updates

Commit Message

David Woodhouse Jan. 6, 2021, 12:23 a.m. UTC

From: Joao Martins <[e-mail]>

Parameterise kvm_setup_pvclock_page() a little bit so that it can be
invoked for different gfn_to_hva_cache structures, and with different
offsets. Then we can invoke it for the normal KVM pvclock and also for
the Xen one in the vcpu_info.

Signed-off-by: Joao Martins <[e-mail]>
Signed-off-by: David Woodhouse <[e-mail]>
---
 arch/x86/kvm/x86.c | 31 ++++++++++++++++++-------------
 arch/x86/kvm/xen.c |  4 ++++
 2 files changed, 22 insertions(+), 13 deletions(-)

Patch

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 761114f19489..228dd5ab9a81 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2588,13 +2588,15 @@  u64 get_kvmclock_ns(struct kvm *kvm)
 	return ret;
 }
 
-static void kvm_setup_pvclock_page(struct kvm_vcpu *v)
+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_cached(v->kvm, &vcpu->pv_time,
-		&guest_hv_clock, sizeof(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
@@ -2617,9 +2619,9 @@  static void kvm_setup_pvclock_page(struct kvm_vcpu *v)
 		++guest_hv_clock.version;  /* first time write, random junk */
 
 	vcpu->hv_clock.version = guest_hv_clock.version + 1;
-	kvm_write_guest_cached(v->kvm, &vcpu->pv_time,
-				&vcpu->hv_clock,
-				sizeof(vcpu->hv_clock.version));
+	kvm_write_guest_offset_cached(v->kvm, cache,
+				      &vcpu->hv_clock, offset,
+				      sizeof(vcpu->hv_clock.version));
 
 	smp_wmb();
 
@@ -2633,16 +2635,16 @@  static void kvm_setup_pvclock_page(struct kvm_vcpu *v)
 
 	trace_kvm_pvclock_update(v->vcpu_id, &vcpu->hv_clock);
 
-	kvm_write_guest_cached(v->kvm, &vcpu->pv_time,
-				&vcpu->hv_clock,
-				sizeof(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_cached(v->kvm, &vcpu->pv_time,
-				&vcpu->hv_clock,
-				sizeof(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)
@@ -2729,7 +2731,10 @@  static int kvm_guest_time_update(struct kvm_vcpu *v)
 	vcpu->hv_clock.flags = pvclock_flags;
 
 	if (vcpu->pv_time_enabled)
-		kvm_setup_pvclock_page(v);
+		kvm_setup_pvclock_page(v, &vcpu->pv_time, 0);
+	if (vcpu->xen.vcpu_info_set)
+		kvm_setup_pvclock_page(v, &vcpu->xen.vcpu_info_cache,
+				       offsetof(struct compat_vcpu_info, time));
 	if (v == kvm_get_vcpu(v->kvm, 0))
 		kvm_hv_setup_tsc_page(v->kvm, &vcpu->hv_clock);
 	return 0;
diff --git a/arch/x86/kvm/xen.c b/arch/x86/kvm/xen.c
index 4bc72e0b9928..d2055b60fdc1 100644
--- a/arch/x86/kvm/xen.c
+++ b/arch/x86/kvm/xen.c
@@ -82,6 +82,9 @@  int kvm_xen_hvm_set_attr(struct kvm *kvm, struct kvm_xen_hvm_attr *data)
 		/* No compat necessary here. */
 		BUILD_BUG_ON(sizeof(struct vcpu_info) !=
 			     sizeof(struct compat_vcpu_info));
+		BUILD_BUG_ON(offsetof(struct vcpu_info, time) !=
+			     offsetof(struct compat_vcpu_info, time));
+
 		r = kvm_gfn_to_hva_cache_init(kvm, &v->arch.xen.vcpu_info_cache,
 					      data->u.vcpu_attr.gpa,
 					      sizeof(struct vcpu_info));
@@ -89,6 +92,7 @@  int kvm_xen_hvm_set_attr(struct kvm *kvm, struct kvm_xen_hvm_attr *data)
 			return r;
 
 		v->arch.xen.vcpu_info_set = true;
+		kvm_make_request(KVM_REQ_CLOCK_UPDATE, v);
 		break;
 
 	default: