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

Pull KVM fixes from Radim Krčmář:
 "ARM:
   - Lazy FPSIMD switching fixes
   - Really disable compat ioctls on architectures that don't want it
   - Disable compat on arm64 (it was never implemented...)
   - Rely on architectural requirements for GICV on GICv3
   - Detect bad alignments in unmap_stage2_range

  x86:
   - Add nested VM entry checks to avoid broken error recovery path
   - Minor documentation fix"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: fix KVM_CAP_HYPERV_TLBFLUSH paragraph number
  kvm: vmx: Nested VM-entry prereqs for event inj.
  KVM: arm64: Prevent KVM_COMPAT from being selected
  KVM: Enforce error in ioctl for compat tasks when !KVM_COMPAT
  KVM: arm/arm64: add WARN_ON if size is not PAGE_SIZE aligned in unmap_stage2_range
  KVM: arm64: Avoid mistaken attempts to save SVE state for vcpus
  KVM: arm64/sve: Fix SVE trap restoration for non-current tasks
  KVM: arm64: Don't mask softirq with IRQs disabled in vcpu_put()
  arm64: Introduce sysreg_clear_set()
  KVM: arm/arm64: Drop resource size check for GICV window

6 files changed, 118 insertions, 9 deletions

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index fda9a8ca48be..fe8777b12f86 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -306,6 +306,7 @@ struct kvm_vcpu_arch {
 #define KVM_ARM64_FP_ENABLED		(1 << 1) /* guest FP regs loaded */
 #define KVM_ARM64_FP_HOST		(1 << 2) /* host FP regs loaded */
 #define KVM_ARM64_HOST_SVE_IN_USE	(1 << 3) /* backup for host TIF_SVE */
+#define KVM_ARM64_HOST_SVE_ENABLED	(1 << 4) /* SVE enabled for EL0 */
 
 #define vcpu_gp_regs(v)		(&(v)->arch.ctxt.gp_regs)
 
diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h
index 6171178075dc..a8f84812c6e8 100644
--- a/arch/arm64/include/asm/sysreg.h
+++ b/arch/arm64/include/asm/sysreg.h
@@ -728,6 +728,17 @@ asm(
 	asm volatile("msr_s " __stringify(r) ", %x0" : : "rZ" (__val));	\
 } while (0)
 
+/*
+ * Modify bits in a sysreg. Bits in the clear mask are zeroed, then bits in the
+ * set mask are set. Other bits are left as-is.
+ */
+#define sysreg_clear_set(sysreg, clear, set) do {			\
+	u64 __scs_val = read_sysreg(sysreg);				\
+	u64 __scs_new = (__scs_val & ~(u64)(clear)) | (set);		\
+	if (__scs_new != __scs_val)					\
+		write_sysreg(__scs_new, sysreg);			\
+} while (0)
+
 static inline void config_sctlr_el1(u32 clear, u32 set)
 {
 	u32 val;
diff --git a/arch/arm64/kvm/fpsimd.c b/arch/arm64/kvm/fpsimd.c
index dc6ecfa5a2d2..aac7808ce216 100644
--- a/arch/arm64/kvm/fpsimd.c
+++ b/arch/arm64/kvm/fpsimd.c
@@ -5,13 +5,14 @@
  * Copyright 2018 Arm Limited
  * Author: Dave Martin <Dave.Martin@arm.com>
  */
-#include <linux/bottom_half.h>
+#include <linux/irqflags.h>
 #include <linux/sched.h>
 #include <linux/thread_info.h>
 #include <linux/kvm_host.h>
 #include <asm/kvm_asm.h>
 #include <asm/kvm_host.h>
 #include <asm/kvm_mmu.h>
+#include <asm/sysreg.h>
 
 /*
  * Called on entry to KVM_RUN unless this vcpu previously ran at least
@@ -61,10 +62,16 @@ void kvm_arch_vcpu_load_fp(struct kvm_vcpu *vcpu)
 {
 	BUG_ON(!current->mm);
 
-	vcpu->arch.flags &= ~(KVM_ARM64_FP_ENABLED | KVM_ARM64_HOST_SVE_IN_USE);
+	vcpu->arch.flags &= ~(KVM_ARM64_FP_ENABLED |
+			      KVM_ARM64_HOST_SVE_IN_USE |
+			      KVM_ARM64_HOST_SVE_ENABLED);
 	vcpu->arch.flags |= KVM_ARM64_FP_HOST;
+
 	if (test_thread_flag(TIF_SVE))
 		vcpu->arch.flags |= KVM_ARM64_HOST_SVE_IN_USE;
+
+	if (read_sysreg(cpacr_el1) & CPACR_EL1_ZEN_EL0EN)
+		vcpu->arch.flags |= KVM_ARM64_HOST_SVE_ENABLED;
 }
 
 /*
@@ -92,19 +99,30 @@ void kvm_arch_vcpu_ctxsync_fp(struct kvm_vcpu *vcpu)
  */
 void kvm_arch_vcpu_put_fp(struct kvm_vcpu *vcpu)
 {
-	local_bh_disable();
+	unsigned long flags;
 
-	update_thread_flag(TIF_SVE,
-			   vcpu->arch.flags & KVM_ARM64_HOST_SVE_IN_USE);
+	local_irq_save(flags);
 
 	if (vcpu->arch.flags & KVM_ARM64_FP_ENABLED) {
 		/* Clean guest FP state to memory and invalidate cpu view */
 		fpsimd_save();
 		fpsimd_flush_cpu_state();
-	} else if (!test_thread_flag(TIF_FOREIGN_FPSTATE)) {
-		/* Ensure user trap controls are correctly restored */
-		fpsimd_bind_task_to_cpu();
+	} else if (system_supports_sve()) {
+		/*
+		 * The FPSIMD/SVE state in the CPU has not been touched, and we
+		 * have SVE (and VHE): CPACR_EL1 (alias CPTR_EL2) has been
+		 * reset to CPACR_EL1_DEFAULT by the Hyp code, disabling SVE
+		 * for EL0.  To avoid spurious traps, restore the trap state
+		 * seen by kvm_arch_vcpu_load_fp():
+		 */
+		if (vcpu->arch.flags & KVM_ARM64_HOST_SVE_ENABLED)
+			sysreg_clear_set(CPACR_EL1, 0, CPACR_EL1_ZEN_EL0EN);
+		else
+			sysreg_clear_set(CPACR_EL1, CPACR_EL1_ZEN_EL0EN, 0);
 	}
 
-	local_bh_enable();
+	update_thread_flag(TIF_SVE,
+			   vcpu->arch.flags & KVM_ARM64_HOST_SVE_IN_USE);
+
+	local_irq_restore(flags);
 }
diff --git a/arch/x86/include/asm/vmx.h b/arch/x86/include/asm/vmx.h
index 425e6b8b9547..6aa8499e1f62 100644
--- a/arch/x86/include/asm/vmx.h
+++ b/arch/x86/include/asm/vmx.h
@@ -114,6 +114,7 @@
 #define VMX_MISC_PREEMPTION_TIMER_RATE_MASK	0x0000001f
 #define VMX_MISC_SAVE_EFER_LMA			0x00000020
 #define VMX_MISC_ACTIVITY_HLT			0x00000040
+#define VMX_MISC_ZERO_LEN_INS			0x40000000
 
 /* VMFUNC functions */
 #define VMX_VMFUNC_EPTP_SWITCHING               0x00000001
@@ -351,11 +352,13 @@ enum vmcs_field {
 #define VECTORING_INFO_VALID_MASK       	INTR_INFO_VALID_MASK
 
 #define INTR_TYPE_EXT_INTR              (0 << 8) /* external interrupt */
+#define INTR_TYPE_RESERVED              (1 << 8) /* reserved */
 #define INTR_TYPE_NMI_INTR		(2 << 8) /* NMI */
 #define INTR_TYPE_HARD_EXCEPTION	(3 << 8) /* processor exception */
 #define INTR_TYPE_SOFT_INTR             (4 << 8) /* software interrupt */
 #define INTR_TYPE_PRIV_SW_EXCEPTION	(5 << 8) /* ICE breakpoint - undocumented */
 #define INTR_TYPE_SOFT_EXCEPTION	(6 << 8) /* software exception */
+#define INTR_TYPE_OTHER_EVENT           (7 << 8) /* other event */
 
 /* GUEST_INTERRUPTIBILITY_INFO flags. */
 #define GUEST_INTR_STATE_STI		0x00000001
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 559a12b6184d..1689f433f3a0 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -1705,6 +1705,17 @@ static inline bool nested_cpu_has_vmwrite_any_field(struct kvm_vcpu *vcpu)
 		MSR_IA32_VMX_MISC_VMWRITE_SHADOW_RO_FIELDS;
 }
 
+static inline bool nested_cpu_has_zero_length_injection(struct kvm_vcpu *vcpu)
+{
+	return to_vmx(vcpu)->nested.msrs.misc_low & VMX_MISC_ZERO_LEN_INS;
+}
+
+static inline bool nested_cpu_supports_monitor_trap_flag(struct kvm_vcpu *vcpu)
+{
+	return to_vmx(vcpu)->nested.msrs.procbased_ctls_high &
+			CPU_BASED_MONITOR_TRAP_FLAG;
+}
+
 static inline bool nested_cpu_has(struct vmcs12 *vmcs12, u32 bit)
 {
 	return vmcs12->cpu_based_vm_exec_control & bit;
@@ -11620,6 +11631,62 @@ static int check_vmentry_prereqs(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12)
 	    !nested_cr3_valid(vcpu, vmcs12->host_cr3))
 		return VMXERR_ENTRY_INVALID_HOST_STATE_FIELD;
 
+	/*
+	 * From the Intel SDM, volume 3:
+	 * Fields relevant to VM-entry event injection must be set properly.
+	 * These fields are the VM-entry interruption-information field, the
+	 * VM-entry exception error code, and the VM-entry instruction length.
+	 */
+	if (vmcs12->vm_entry_intr_info_field & INTR_INFO_VALID_MASK) {
+		u32 intr_info = vmcs12->vm_entry_intr_info_field;
+		u8 vector = intr_info & INTR_INFO_VECTOR_MASK;
+		u32 intr_type = intr_info & INTR_INFO_INTR_TYPE_MASK;
+		bool has_error_code = intr_info & INTR_INFO_DELIVER_CODE_MASK;
+		bool should_have_error_code;
+		bool urg = nested_cpu_has2(vmcs12,
+					   SECONDARY_EXEC_UNRESTRICTED_GUEST);
+		bool prot_mode = !urg || vmcs12->guest_cr0 & X86_CR0_PE;
+
+		/* VM-entry interruption-info field: interruption type */
+		if (intr_type == INTR_TYPE_RESERVED ||
+		    (intr_type == INTR_TYPE_OTHER_EVENT &&
+		     !nested_cpu_supports_monitor_trap_flag(vcpu)))
+			return VMXERR_ENTRY_INVALID_CONTROL_FIELD;
+
+		/* VM-entry interruption-info field: vector */
+		if ((intr_type == INTR_TYPE_NMI_INTR && vector != NMI_VECTOR) ||
+		    (intr_type == INTR_TYPE_HARD_EXCEPTION && vector > 31) ||
+		    (intr_type == INTR_TYPE_OTHER_EVENT && vector != 0))
+			return VMXERR_ENTRY_INVALID_CONTROL_FIELD;
+
+		/* VM-entry interruption-info field: deliver error code */
+		should_have_error_code =
+			intr_type == INTR_TYPE_HARD_EXCEPTION && prot_mode &&
+			x86_exception_has_error_code(vector);
+		if (has_error_code != should_have_error_code)
+			return VMXERR_ENTRY_INVALID_CONTROL_FIELD;
+
+		/* VM-entry exception error code */
+		if (has_error_code &&
+		    vmcs12->vm_entry_exception_error_code & GENMASK(31, 15))
+			return VMXERR_ENTRY_INVALID_CONTROL_FIELD;
+
+		/* VM-entry interruption-info field: reserved bits */
+		if (intr_info & INTR_INFO_RESVD_BITS_MASK)
+			return VMXERR_ENTRY_INVALID_CONTROL_FIELD;
+
+		/* VM-entry instruction length */
+		switch (intr_type) {
+		case INTR_TYPE_SOFT_EXCEPTION:
+		case INTR_TYPE_SOFT_INTR:
+		case INTR_TYPE_PRIV_SW_EXCEPTION:
+			if ((vmcs12->vm_entry_instruction_len > 15) ||
+			    (vmcs12->vm_entry_instruction_len == 0 &&
+			     !nested_cpu_has_zero_length_injection(vcpu)))
+				return VMXERR_ENTRY_INVALID_CONTROL_FIELD;
+		}
+	}
+
 	return 0;
 }
 
diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h
index 331993c49dae..257f27620bc2 100644
--- a/arch/x86/kvm/x86.h
+++ b/arch/x86/kvm/x86.h
@@ -110,6 +110,15 @@ static inline bool is_la57_mode(struct kvm_vcpu *vcpu)
 #endif
 }
 
+static inline bool x86_exception_has_error_code(unsigned int vector)
+{
+	static u32 exception_has_error_code = BIT(DF_VECTOR) | BIT(TS_VECTOR) |
+			BIT(NP_VECTOR) | BIT(SS_VECTOR) | BIT(GP_VECTOR) |
+			BIT(PF_VECTOR) | BIT(AC_VECTOR);
+
+	return (1U << vector) & exception_has_error_code;
+}
+
 static inline bool mmu_is_nested(struct kvm_vcpu *vcpu)
 {
 	return vcpu->arch.walk_mmu == &vcpu->arch.nested_mmu;