Merge git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm fixes from Marcelo Tosatti.

* git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: Fix bounds checking in ioapic indirect register reads (CVE-2013-1798)
  KVM: x86: Convert MSR_KVM_SYSTEM_TIME to use gfn_to_hva_cache functions (CVE-2013-1797)
  KVM: x86: fix for buffer overflow in handling of MSR_KVM_SYSTEM_TIME (CVE-2013-1796)
  KVM: x86: fix deadlock in clock-in-progress request handling
  KVM: allow host header to be included even for !CONFIG_KVM

4 files changed, 44 insertions, 38 deletions

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 635a74d2240..4979778cc7f 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -414,8 +414,8 @@ struct kvm_vcpu_arch {
 	gpa_t time;
 	struct pvclock_vcpu_time_info hv_clock;
 	unsigned int hw_tsc_khz;
-	unsigned int time_offset;
-	struct page *time_page;
+	struct gfn_to_hva_cache pv_time;
+	bool pv_time_enabled;
 	/* set guest stopped flag in pvclock flags field */
 	bool pvclock_set_guest_stopped_request;
 
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index f71500af1f8..f19ac0aca60 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1406,25 +1406,15 @@ static int kvm_guest_time_update(struct kvm_vcpu *v)
 	unsigned long flags, this_tsc_khz;
 	struct kvm_vcpu_arch *vcpu = &v->arch;
 	struct kvm_arch *ka = &v->kvm->arch;
-	void *shared_kaddr;
 	s64 kernel_ns, max_kernel_ns;
 	u64 tsc_timestamp, host_tsc;
-	struct pvclock_vcpu_time_info *guest_hv_clock;
+	struct pvclock_vcpu_time_info guest_hv_clock;
 	u8 pvclock_flags;
 	bool use_master_clock;
 
 	kernel_ns = 0;
 	host_tsc = 0;
 
-	/* Keep irq disabled to prevent changes to the clock */
-	local_irq_save(flags);
-	this_tsc_khz = __get_cpu_var(cpu_tsc_khz);
-	if (unlikely(this_tsc_khz == 0)) {
-		local_irq_restore(flags);
-		kvm_make_request(KVM_REQ_CLOCK_UPDATE, v);
-		return 1;
-	}
-
 	/*
 	 * If the host uses TSC clock, then passthrough TSC as stable
 	 * to the guest.
@@ -1436,6 +1426,15 @@ static int kvm_guest_time_update(struct kvm_vcpu *v)
 		kernel_ns = ka->master_kernel_ns;
 	}
 	spin_unlock(&ka->pvclock_gtod_sync_lock);
+
+	/* Keep irq disabled to prevent changes to the clock */
+	local_irq_save(flags);
+	this_tsc_khz = __get_cpu_var(cpu_tsc_khz);
+	if (unlikely(this_tsc_khz == 0)) {
+		local_irq_restore(flags);
+		kvm_make_request(KVM_REQ_CLOCK_UPDATE, v);
+		return 1;
+	}
 	if (!use_master_clock) {
 		host_tsc = native_read_tsc();
 		kernel_ns = get_kernel_ns();
@@ -1463,7 +1462,7 @@ static int kvm_guest_time_update(struct kvm_vcpu *v)
 
 	local_irq_restore(flags);
 
-	if (!vcpu->time_page)
+	if (!vcpu->pv_time_enabled)
 		return 0;
 
 	/*
@@ -1525,12 +1524,12 @@ static int kvm_guest_time_update(struct kvm_vcpu *v)
 	 */
 	vcpu->hv_clock.version += 2;
 
-	shared_kaddr = kmap_atomic(vcpu->time_page);
-
-	guest_hv_clock = shared_kaddr + vcpu->time_offset;
+	if (unlikely(kvm_read_guest_cached(v->kvm, &vcpu->pv_time,
+		&guest_hv_clock, sizeof(guest_hv_clock))))
+		return 0;
 
 	/* retain PVCLOCK_GUEST_STOPPED if set in guest copy */
-	pvclock_flags = (guest_hv_clock->flags & PVCLOCK_GUEST_STOPPED);
+	pvclock_flags = (guest_hv_clock.flags & PVCLOCK_GUEST_STOPPED);
 
 	if (vcpu->pvclock_set_guest_stopped_request) {
 		pvclock_flags |= PVCLOCK_GUEST_STOPPED;
@@ -1543,12 +1542,9 @@ static int kvm_guest_time_update(struct kvm_vcpu *v)
 
 	vcpu->hv_clock.flags = pvclock_flags;
 
-	memcpy(shared_kaddr + vcpu->time_offset, &vcpu->hv_clock,
-	       sizeof(vcpu->hv_clock));
-
-	kunmap_atomic(shared_kaddr);
-
-	mark_page_dirty(v->kvm, vcpu->time >> PAGE_SHIFT);
+	kvm_write_guest_cached(v->kvm, &vcpu->pv_time,
+				&vcpu->hv_clock,
+				sizeof(vcpu->hv_clock));
 	return 0;
 }
 
@@ -1837,10 +1833,7 @@ static int kvm_pv_enable_async_pf(struct kvm_vcpu *vcpu, u64 data)
 
 static void kvmclock_reset(struct kvm_vcpu *vcpu)
 {
-	if (vcpu->arch.time_page) {
-		kvm_release_page_dirty(vcpu->arch.time_page);
-		vcpu->arch.time_page = NULL;
-	}
+	vcpu->arch.pv_time_enabled = false;
 }
 
 static void accumulate_steal_time(struct kvm_vcpu *vcpu)
@@ -1947,6 +1940,7 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 		break;
 	case MSR_KVM_SYSTEM_TIME_NEW:
 	case MSR_KVM_SYSTEM_TIME: {
+		u64 gpa_offset;
 		kvmclock_reset(vcpu);
 
 		vcpu->arch.time = data;
@@ -1956,14 +1950,17 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 		if (!(data & 1))
 			break;
 
-		/* ...but clean it before doing the actual write */
-		vcpu->arch.time_offset = data & ~(PAGE_MASK | 1);
+		gpa_offset = data & ~(PAGE_MASK | 1);
 
-		vcpu->arch.time_page =
-				gfn_to_page(vcpu->kvm, data >> PAGE_SHIFT);
+		/* Check that the address is 32-byte aligned. */
+		if (gpa_offset & (sizeof(struct pvclock_vcpu_time_info) - 1))
+			break;
 
-		if (is_error_page(vcpu->arch.time_page))
-			vcpu->arch.time_page = NULL;
+		if (kvm_gfn_to_hva_cache_init(vcpu->kvm,
+		     &vcpu->arch.pv_time, data & ~1ULL))
+			vcpu->arch.pv_time_enabled = false;
+		else
+			vcpu->arch.pv_time_enabled = true;
 
 		break;
 	}
@@ -2967,7 +2964,7 @@ static int kvm_vcpu_ioctl_x86_set_xcrs(struct kvm_vcpu *vcpu,
  */
 static int kvm_set_guest_paused(struct kvm_vcpu *vcpu)
 {
-	if (!vcpu->arch.time_page)
+	if (!vcpu->arch.pv_time_enabled)
 		return -EINVAL;
 	vcpu->arch.pvclock_set_guest_stopped_request = true;
 	kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);
@@ -6718,6 +6715,7 @@ int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
 		goto fail_free_wbinvd_dirty_mask;
 
 	vcpu->arch.ia32_tsc_adjust_msr = 0x0;
+	vcpu->arch.pv_time_enabled = false;
 	kvm_async_pf_hash_reset(vcpu);
 	kvm_pmu_init(vcpu);
 
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index cad77fe09d7..a9428635c9f 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -1,6 +1,8 @@
 #ifndef __KVM_HOST_H
 #define __KVM_HOST_H
 
+#if IS_ENABLED(CONFIG_KVM)
+
 /*
  * This work is licensed under the terms of the GNU GPL, version 2.  See
  * the COPYING file in the top-level directory.
@@ -1055,5 +1057,8 @@ static inline bool kvm_vcpu_eligible_for_directed_yield(struct kvm_vcpu *vcpu)
 }
 
 #endif /* CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT */
+#else
+static inline void __guest_enter(void) { return; }
+static inline void __guest_exit(void) { return; }
+#endif /* IS_ENABLED(CONFIG_KVM) */
 #endif
-
diff --git a/virt/kvm/ioapic.c b/virt/kvm/ioapic.c
index ce82b940195..5ba005c00e2 100644
--- a/virt/kvm/ioapic.c
+++ b/virt/kvm/ioapic.c
@@ -74,9 +74,12 @@ static unsigned long ioapic_read_indirect(struct kvm_ioapic *ioapic,
 			u32 redir_index = (ioapic->ioregsel - 0x10) >> 1;
 			u64 redir_content;
 
-			ASSERT(redir_index < IOAPIC_NUM_PINS);
+			if (redir_index < IOAPIC_NUM_PINS)
+				redir_content =
+					ioapic->redirtbl[redir_index].bits;
+			else
+				redir_content = ~0ULL;
 
-			redir_content = ioapic->redirtbl[redir_index].bits;
 			result = (ioapic->ioregsel & 0x1) ?
 			    (redir_content >> 32) & 0xffffffff :
 			    redir_content & 0xffffffff;