Merge branch 'kvm-ppc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc

This fix was intended for 4.13, but didn't get in because both
maintainers were on vacation.

Paul Mackerras:
 "It adds mutual exclusion between list_add_rcu and list_del_rcu calls
  on the kvm->arch.spapr_tce_tables list.  Without this, userspace could
  potentially trigger corruption of the list and cause a host crash or
  worse."

6 files changed, 25 insertions, 35 deletions

diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 1cea3ffba82d..0099e10eb045 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -474,7 +474,7 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
 			entry->ecx &= kvm_cpuid_7_0_ecx_x86_features;
 			cpuid_mask(&entry->ecx, CPUID_7_ECX);
 			/* PKU is not yet implemented for shadow paging. */
-			if (!tdp_enabled)
+			if (!tdp_enabled || !boot_cpu_has(X86_FEATURE_OSPKE))
 				entry->ecx &= ~F(PKU);
 			entry->edx &= kvm_cpuid_7_0_edx_x86_features;
 			entry->edx &= get_scattered_cpuid_leaf(7, 0, CPUID_EDX);
diff --git a/arch/x86/kvm/kvm_cache_regs.h b/arch/x86/kvm/kvm_cache_regs.h
index 0052317b2733..9add410f195f 100644
--- a/arch/x86/kvm/kvm_cache_regs.h
+++ b/arch/x86/kvm/kvm_cache_regs.h
@@ -84,11 +84,6 @@ static inline u64 kvm_read_edx_eax(struct kvm_vcpu *vcpu)
 		| ((u64)(kvm_register_read(vcpu, VCPU_REGS_RDX) & -1u) << 32);
 }
 
-static inline u32 kvm_read_pkru(struct kvm_vcpu *vcpu)
-{
-	return kvm_x86_ops->get_pkru(vcpu);
-}
-
 static inline void enter_guest_mode(struct kvm_vcpu *vcpu)
 {
 	vcpu->arch.hflags |= HF_GUEST_MASK;
diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h
index e2999f57bfc4..64a2dbd2b1af 100644
--- a/arch/x86/kvm/mmu.h
+++ b/arch/x86/kvm/mmu.h
@@ -172,7 +172,7 @@ static inline u8 permission_fault(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu,
 		* index of the protection domain, so pte_pkey * 2 is
 		* is the index of the first bit for the domain.
 		*/
-		pkru_bits = (kvm_read_pkru(vcpu) >> (pte_pkey * 2)) & 3;
+		pkru_bits = (vcpu->arch.pkru >> (pte_pkey * 2)) & 3;
 
 		/* clear present bit, replace PFEC.RSVD with ACC_USER_MASK. */
 		offset = (pfec & ~1) +
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 9f6fb0ef206c..968f38dcb864 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1117,7 +1117,7 @@ static __init int svm_hardware_setup(void)
 
 	if (vls) {
 		if (!npt_enabled ||
-		    !boot_cpu_has(X86_FEATURE_VIRTUAL_VMLOAD_VMSAVE) ||
+		    !boot_cpu_has(X86_FEATURE_V_VMSAVE_VMLOAD) ||
 		    !IS_ENABLED(CONFIG_X86_64)) {
 			vls = false;
 		} else {
@@ -1790,11 +1790,6 @@ static void svm_set_rflags(struct kvm_vcpu *vcpu, unsigned long rflags)
 	to_svm(vcpu)->vmcb->save.rflags = rflags;
 }
 
-static u32 svm_get_pkru(struct kvm_vcpu *vcpu)
-{
-	return 0;
-}
-
 static void svm_cache_reg(struct kvm_vcpu *vcpu, enum kvm_reg reg)
 {
 	switch (reg) {
@@ -5436,8 +5431,6 @@ static struct kvm_x86_ops svm_x86_ops __ro_after_init = {
 	.get_rflags = svm_get_rflags,
 	.set_rflags = svm_set_rflags,
 
-	.get_pkru = svm_get_pkru,
-
 	.tlb_flush = svm_flush_tlb,
 
 	.run = svm_vcpu_run,
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index ec6b1932dea9..c6efc1f88b25 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -641,8 +641,6 @@ struct vcpu_vmx {
 
 	u64 current_tsc_ratio;
 
-	bool guest_pkru_valid;
-	u32 guest_pkru;
 	u32 host_pkru;
 
 	/*
@@ -2398,11 +2396,6 @@ static void vmx_set_rflags(struct kvm_vcpu *vcpu, unsigned long rflags)
 		to_vmx(vcpu)->emulation_required = emulation_required(vcpu);
 }
 
-static u32 vmx_get_pkru(struct kvm_vcpu *vcpu)
-{
-	return to_vmx(vcpu)->guest_pkru;
-}
-
 static u32 vmx_get_interrupt_shadow(struct kvm_vcpu *vcpu)
 {
 	u32 interruptibility = vmcs_read32(GUEST_INTERRUPTIBILITY_INFO);
@@ -9291,8 +9284,10 @@ static void __noclone vmx_vcpu_run(struct kvm_vcpu *vcpu)
 	if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP)
 		vmx_set_interrupt_shadow(vcpu, 0);
 
-	if (vmx->guest_pkru_valid)
-		__write_pkru(vmx->guest_pkru);
+	if (static_cpu_has(X86_FEATURE_PKU) &&
+	    kvm_read_cr4_bits(vcpu, X86_CR4_PKE) &&
+	    vcpu->arch.pkru != vmx->host_pkru)
+		__write_pkru(vcpu->arch.pkru);
 
 	atomic_switch_perf_msrs(vmx);
 	debugctlmsr = get_debugctlmsr();
@@ -9440,13 +9435,11 @@ static void __noclone vmx_vcpu_run(struct kvm_vcpu *vcpu)
 	 * back on host, so it is safe to read guest PKRU from current
 	 * XSAVE.
 	 */
-	if (boot_cpu_has(X86_FEATURE_OSPKE)) {
-		vmx->guest_pkru = __read_pkru();
-		if (vmx->guest_pkru != vmx->host_pkru) {
-			vmx->guest_pkru_valid = true;
+	if (static_cpu_has(X86_FEATURE_PKU) &&
+	    kvm_read_cr4_bits(vcpu, X86_CR4_PKE)) {
+		vcpu->arch.pkru = __read_pkru();
+		if (vcpu->arch.pkru != vmx->host_pkru)
 			__write_pkru(vmx->host_pkru);
-		} else
-			vmx->guest_pkru_valid = false;
 	}
 
 	/*
@@ -11964,8 +11957,6 @@ static struct kvm_x86_ops vmx_x86_ops __ro_after_init = {
 	.get_rflags = vmx_get_rflags,
 	.set_rflags = vmx_set_rflags,
 
-	.get_pkru = vmx_get_pkru,
-
 	.tlb_flush = vmx_flush_tlb,
 
 	.run = vmx_vcpu_run,
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 3abaff61829d..afd9525b4b7c 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3269,7 +3269,12 @@ static void fill_xsave(u8 *dest, struct kvm_vcpu *vcpu)
 			u32 size, offset, ecx, edx;
 			cpuid_count(XSTATE_CPUID, index,
 				    &size, &offset, &ecx, &edx);
-			memcpy(dest + offset, src, size);
+			if (feature == XFEATURE_MASK_PKRU)
+				memcpy(dest + offset, &vcpu->arch.pkru,
+				       sizeof(vcpu->arch.pkru));
+			else
+				memcpy(dest + offset, src, size);
+
 		}
 
 		valid -= feature;
@@ -3307,7 +3312,11 @@ static void load_xsave(struct kvm_vcpu *vcpu, u8 *src)
 			u32 size, offset, ecx, edx;
 			cpuid_count(XSTATE_CPUID, index,
 				    &size, &offset, &ecx, &edx);
-			memcpy(dest, src + offset, size);
+			if (feature == XFEATURE_MASK_PKRU)
+				memcpy(&vcpu->arch.pkru, src + offset,
+				       sizeof(vcpu->arch.pkru));
+			else
+				memcpy(dest, src + offset, size);
 		}
 
 		valid -= feature;
@@ -7667,7 +7676,9 @@ void kvm_load_guest_fpu(struct kvm_vcpu *vcpu)
 	 */
 	vcpu->guest_fpu_loaded = 1;
 	__kernel_fpu_begin();
-	__copy_kernel_to_fpregs(&vcpu->arch.guest_fpu.state);
+	/* PKRU is separately restored in kvm_x86_ops->run.  */
+	__copy_kernel_to_fpregs(&vcpu->arch.guest_fpu.state,
+				~XFEATURE_MASK_PKRU);
 	trace_kvm_fpu(1);
 }