Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM fixes from Radim Krčmář:
 "ARM fixes:
   - Wrong indentation in the PMU code from the merge window
   - A long-time bug occuring with running ntpd on the host, candidate
     for stable
   - Properly handle (and warn about) the unsupported configuration of
     running on systems with less than 40 bits of PA space
   - More fixes to the PM and hotplug notifier stuff from the merge
     window

  x86:
   - leak of guest xcr0 (typically shows up as SIGILL)
   - new maintainer (who is sending the pull request too)
   - fix for merge window regression
   - fix for guest CPUID"

Paolo Bonzini points out:
 "For the record, this tag is signed by me because I prepared the pull
  request.  Further pull requests for 4.6 will be signed and sent out by
  Radim directly"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: x86: mask CPUID(0xD,0x1).EAX against host value
  kvm: x86: do not leak guest xcr0 into host interrupt handlers
  KVM: MMU: fix permission_fault()
  KVM: new maintainer on the block
  arm64: KVM: unregister notifiers in hyp mode teardown path
  arm64: KVM: Warn when PARange is less than 40 bits
  KVM: arm/arm64: Handle forward time correction gracefully
  arm64: KVM: Add braces to multi-line if statement in virtual PMU code

4 files changed, 10 insertions, 12 deletions

diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 8efb839..bbbaa80 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -534,6 +534,7 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
 			do_cpuid_1_ent(&entry[i], function, idx);
 			if (idx == 1) {
 				entry[i].eax &= kvm_cpuid_D_1_eax_x86_features;
+				cpuid_mask(&entry[i].eax, CPUID_D_1_EAX);
 				entry[i].ebx = 0;
 				if (entry[i].eax & (F(XSAVES)|F(XSAVEC)))
 					entry[i].ebx =
diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h
index b70df72..66b33b9 100644
--- a/arch/x86/kvm/mmu.h
+++ b/arch/x86/kvm/mmu.h
@@ -173,10 +173,9 @@ static inline u8 permission_fault(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu,
 	int index = (pfec >> 1) +
 		    (smap >> (X86_EFLAGS_AC_BIT - PFERR_RSVD_BIT + 1));
 	bool fault = (mmu->permissions[index] >> pte_access) & 1;
+	u32 errcode = PFERR_PRESENT_MASK;
 
 	WARN_ON(pfec & (PFERR_PK_MASK | PFERR_RSVD_MASK));
-	pfec |= PFERR_PRESENT_MASK;
-
 	if (unlikely(mmu->pkru_mask)) {
 		u32 pkru_bits, offset;
 
@@ -189,15 +188,15 @@ static inline u8 permission_fault(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu,
 		pkru_bits = (kvm_read_pkru(vcpu) >> (pte_pkey * 2)) & 3;
 
 		/* clear present bit, replace PFEC.RSVD with ACC_USER_MASK. */
-		offset = pfec - 1 +
+		offset = (pfec & ~1) +
 			((pte_access & PT_USER_MASK) << (PFERR_RSVD_BIT - PT_USER_SHIFT));
 
 		pkru_bits &= mmu->pkru_mask >> offset;
-		pfec |= -pkru_bits & PFERR_PK_MASK;
+		errcode |= -pkru_bits & PFERR_PK_MASK;
 		fault |= (pkru_bits != 0);
 	}
 
-	return -(uint32_t)fault & pfec;
+	return -(u32)fault & errcode;
 }
 
 void kvm_mmu_invalidate_zap_all_pages(struct kvm *kvm);
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index 1d971c7..bc019f7 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -360,7 +360,7 @@ retry_walk:
 			goto error;
 
 		if (unlikely(is_rsvd_bits_set(mmu, pte, walker->level))) {
-			errcode |= PFERR_RSVD_MASK | PFERR_PRESENT_MASK;
+			errcode = PFERR_RSVD_MASK | PFERR_PRESENT_MASK;
 			goto error;
 		}
 
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 0a2c70e..9b7798c 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -700,7 +700,6 @@ static int __kvm_set_xcr(struct kvm_vcpu *vcpu, u32 index, u64 xcr)
 		if ((xcr0 & XFEATURE_MASK_AVX512) != XFEATURE_MASK_AVX512)
 			return 1;
 	}
-	kvm_put_guest_xcr0(vcpu);
 	vcpu->arch.xcr0 = xcr0;
 
 	if ((xcr0 ^ old_xcr0) & XFEATURE_MASK_EXTEND)
@@ -6590,8 +6589,6 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
 	kvm_x86_ops->prepare_guest_switch(vcpu);
 	if (vcpu->fpu_active)
 		kvm_load_guest_fpu(vcpu);
-	kvm_load_guest_xcr0(vcpu);
-
 	vcpu->mode = IN_GUEST_MODE;
 
 	srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
@@ -6618,6 +6615,8 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
 		goto cancel_injection;
 	}
 
+	kvm_load_guest_xcr0(vcpu);
+
 	if (req_immediate_exit)
 		smp_send_reschedule(vcpu->cpu);
 
@@ -6667,6 +6666,8 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
 	vcpu->mode = OUTSIDE_GUEST_MODE;
 	smp_wmb();
 
+	kvm_put_guest_xcr0(vcpu);
+
 	/* Interrupt is enabled by handle_external_intr() */
 	kvm_x86_ops->handle_external_intr(vcpu);
 
@@ -7314,7 +7315,6 @@ void kvm_load_guest_fpu(struct kvm_vcpu *vcpu)
 	 * and assume host would use all available bits.
 	 * Guest xcr0 would be loaded later.
 	 */
-	kvm_put_guest_xcr0(vcpu);
 	vcpu->guest_fpu_loaded = 1;
 	__kernel_fpu_begin();
 	__copy_kernel_to_fpregs(&vcpu->arch.guest_fpu.state);
@@ -7323,8 +7323,6 @@ void kvm_load_guest_fpu(struct kvm_vcpu *vcpu)
 
 void kvm_put_guest_fpu(struct kvm_vcpu *vcpu)
 {
-	kvm_put_guest_xcr0(vcpu);
-
 	if (!vcpu->guest_fpu_loaded) {
 		vcpu->fpu_counter = 0;
 		return;