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

Pull kvm fixes from Paolo Bonzini:
 "The main and larger change here is a workaround for AMD's lack of
  cache coherency for encrypted-memory guests.

  I have another patch pending, but it's waiting for review from the
  architecture maintainers.

  RISC-V:

   - Remove 's' & 'u' as valid ISA extension

   - Do not allow disabling the base extensions 'i'/'m'/'a'/'c'

  x86:

   - Fix NMI watchdog in guests on AMD

   - Fix for SEV cache incoherency issues

   - Don't re-acquire SRCU lock in complete_emulated_io()

   - Avoid NULL pointer deref if VM creation fails

   - Fix race conditions between APICv disabling and vCPU creation

   - Bugfixes for disabling of APICv

   - Preserve BSP MSR_KVM_POLL_CONTROL across suspend/resume

  selftests:

   - Do not use bitfields larger than 32-bits, they differ between GCC
     and clang"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  kvm: selftests: introduce and use more page size-related constants
  kvm: selftests: do not use bitfields larger than 32-bits for PTEs
  KVM: SEV: add cache flush to solve SEV cache incoherency issues
  KVM: SVM: Flush when freeing encrypted pages even on SME_COHERENT CPUs
  KVM: SVM: Simplify and harden helper to flush SEV guest page(s)
  KVM: selftests: Silence compiler warning in the kvm_page_table_test
  KVM: x86/pmu: Update AMD PMC sample period to fix guest NMI-watchdog
  x86/kvm: Preserve BSP MSR_KVM_POLL_CONTROL across suspend/resume
  KVM: SPDX style and spelling fixes
  KVM: x86: Skip KVM_GUESTDBG_BLOCKIRQ APICv update if APICv is disabled
  KVM: x86: Pend KVM_REQ_APICV_UPDATE during vCPU creation to fix a race
  KVM: nVMX: Defer APICv updates while L2 is active until L1 is active
  KVM: x86: Tag APICv DISABLE inhibit, not ABSENT, if APICv is disabled
  KVM: Initialize debugfs_dentry when a VM is created to avoid NULL deref
  KVM: Add helpers to wrap vcpu->srcu_idx and yell if it's abused
  KVM: RISC-V: Use kvm_vcpu.srcu_idx, drop RISC-V's unnecessary copy
  KVM: x86: Don't re-acquire SRCU lock in complete_emulated_io()
  RISC-V: KVM: Restrict the extensions that can be disabled
  RISC-V: KVM: Remove 's' & 'u' as valid ISA extension

1 files changed, 37 insertions, 23 deletions

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 547ba00ef64f..a6ab19afc638 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -9111,7 +9111,7 @@ static void kvm_apicv_init(struct kvm *kvm)
 
 	if (!enable_apicv)
 		set_or_clear_apicv_inhibit(inhibits,
-					   APICV_INHIBIT_REASON_ABSENT, true);
+					   APICV_INHIBIT_REASON_DISABLE, true);
 }
 
 static void kvm_sched_yield(struct kvm_vcpu *vcpu, unsigned long dest_id)
@@ -9889,6 +9889,11 @@ void kvm_arch_mmu_notifier_invalidate_range(struct kvm *kvm,
 		kvm_make_all_cpus_request(kvm, KVM_REQ_APIC_PAGE_RELOAD);
 }
 
+void kvm_arch_guest_memory_reclaimed(struct kvm *kvm)
+{
+	static_call_cond(kvm_x86_guest_memory_reclaimed)(kvm);
+}
+
 static void kvm_vcpu_reload_apic_access_page(struct kvm_vcpu *vcpu)
 {
 	if (!lapic_in_kernel(vcpu))
@@ -10097,7 +10102,7 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
 	/* Store vcpu->apicv_active before vcpu->mode.  */
 	smp_store_release(&vcpu->mode, IN_GUEST_MODE);
 
-	srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
+	kvm_vcpu_srcu_read_unlock(vcpu);
 
 	/*
 	 * 1) We should set ->mode before checking ->requests.  Please see
@@ -10128,7 +10133,7 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
 		smp_wmb();
 		local_irq_enable();
 		preempt_enable();
-		vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
+		kvm_vcpu_srcu_read_lock(vcpu);
 		r = 1;
 		goto cancel_injection;
 	}
@@ -10254,7 +10259,7 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
 	local_irq_enable();
 	preempt_enable();
 
-	vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
+	kvm_vcpu_srcu_read_lock(vcpu);
 
 	/*
 	 * Profile KVM exit RIPs:
@@ -10284,7 +10289,7 @@ out:
 }
 
 /* Called within kvm->srcu read side.  */
-static inline int vcpu_block(struct kvm *kvm, struct kvm_vcpu *vcpu)
+static inline int vcpu_block(struct kvm_vcpu *vcpu)
 {
 	bool hv_timer;
 
@@ -10300,12 +10305,12 @@ static inline int vcpu_block(struct kvm *kvm, struct kvm_vcpu *vcpu)
 		if (hv_timer)
 			kvm_lapic_switch_to_sw_timer(vcpu);
 
-		srcu_read_unlock(&kvm->srcu, vcpu->srcu_idx);
+		kvm_vcpu_srcu_read_unlock(vcpu);
 		if (vcpu->arch.mp_state == KVM_MP_STATE_HALTED)
 			kvm_vcpu_halt(vcpu);
 		else
 			kvm_vcpu_block(vcpu);
-		vcpu->srcu_idx = srcu_read_lock(&kvm->srcu);
+		kvm_vcpu_srcu_read_lock(vcpu);
 
 		if (hv_timer)
 			kvm_lapic_switch_to_hv_timer(vcpu);
@@ -10347,7 +10352,6 @@ static inline bool kvm_vcpu_running(struct kvm_vcpu *vcpu)
 static int vcpu_run(struct kvm_vcpu *vcpu)
 {
 	int r;
-	struct kvm *kvm = vcpu->kvm;
 
 	vcpu->arch.l1tf_flush_l1d = true;
 
@@ -10355,7 +10359,7 @@ static int vcpu_run(struct kvm_vcpu *vcpu)
 		if (kvm_vcpu_running(vcpu)) {
 			r = vcpu_enter_guest(vcpu);
 		} else {
-			r = vcpu_block(kvm, vcpu);
+			r = vcpu_block(vcpu);
 		}
 
 		if (r <= 0)
@@ -10374,9 +10378,9 @@ static int vcpu_run(struct kvm_vcpu *vcpu)
 		}
 
 		if (__xfer_to_guest_mode_work_pending()) {
-			srcu_read_unlock(&kvm->srcu, vcpu->srcu_idx);
+			kvm_vcpu_srcu_read_unlock(vcpu);
 			r = xfer_to_guest_mode_handle_work(vcpu);
-			vcpu->srcu_idx = srcu_read_lock(&kvm->srcu);
+			kvm_vcpu_srcu_read_lock(vcpu);
 			if (r)
 				return r;
 		}
@@ -10387,12 +10391,7 @@ static int vcpu_run(struct kvm_vcpu *vcpu)
 
 static inline int complete_emulated_io(struct kvm_vcpu *vcpu)
 {
-	int r;
-
-	vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
-	r = kvm_emulate_instruction(vcpu, EMULTYPE_NO_DECODE);
-	srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
-	return r;
+	return kvm_emulate_instruction(vcpu, EMULTYPE_NO_DECODE);
 }
 
 static int complete_emulated_pio(struct kvm_vcpu *vcpu)
@@ -10484,7 +10483,6 @@ static void kvm_put_guest_fpu(struct kvm_vcpu *vcpu)
 int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
 {
 	struct kvm_run *kvm_run = vcpu->run;
-	struct kvm *kvm = vcpu->kvm;
 	int r;
 
 	vcpu_load(vcpu);
@@ -10492,7 +10490,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
 	kvm_run->flags = 0;
 	kvm_load_guest_fpu(vcpu);
 
-	vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
+	kvm_vcpu_srcu_read_lock(vcpu);
 	if (unlikely(vcpu->arch.mp_state == KVM_MP_STATE_UNINITIALIZED)) {
 		if (kvm_run->immediate_exit) {
 			r = -EINTR;
@@ -10504,9 +10502,9 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
 		 */
 		WARN_ON_ONCE(kvm_lapic_hv_timer_in_use(vcpu));
 
-		srcu_read_unlock(&kvm->srcu, vcpu->srcu_idx);
+		kvm_vcpu_srcu_read_unlock(vcpu);
 		kvm_vcpu_block(vcpu);
-		vcpu->srcu_idx = srcu_read_lock(&kvm->srcu);
+		kvm_vcpu_srcu_read_lock(vcpu);
 
 		if (kvm_apic_accept_events(vcpu) < 0) {
 			r = 0;
@@ -10567,7 +10565,7 @@ out:
 	if (kvm_run->kvm_valid_regs)
 		store_regs(vcpu);
 	post_kvm_run_save(vcpu);
-	srcu_read_unlock(&kvm->srcu, vcpu->srcu_idx);
+	kvm_vcpu_srcu_read_unlock(vcpu);
 
 	kvm_sigset_deactivate(vcpu);
 	vcpu_put(vcpu);
@@ -10985,6 +10983,9 @@ static void kvm_arch_vcpu_guestdbg_update_apicv_inhibit(struct kvm *kvm)
 	struct kvm_vcpu *vcpu;
 	unsigned long i;
 
+	if (!enable_apicv)
+		return;
+
 	down_write(&kvm->arch.apicv_update_lock);
 
 	kvm_for_each_vcpu(i, vcpu, kvm) {
@@ -11196,8 +11197,21 @@ int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu)
 		r = kvm_create_lapic(vcpu, lapic_timer_advance_ns);
 		if (r < 0)
 			goto fail_mmu_destroy;
-		if (kvm_apicv_activated(vcpu->kvm))
+
+		/*
+		 * Defer evaluating inhibits until the vCPU is first run, as
+		 * this vCPU will not get notified of any changes until this
+		 * vCPU is visible to other vCPUs (marked online and added to
+		 * the set of vCPUs).  Opportunistically mark APICv active as
+		 * VMX in particularly is highly unlikely to have inhibits.
+		 * Ignore the current per-VM APICv state so that vCPU creation
+		 * is guaranteed to run with a deterministic value, the request
+		 * will ensure the vCPU gets the correct state before VM-Entry.
+		 */
+		if (enable_apicv) {
 			vcpu->arch.apicv_active = true;
+			kvm_make_request(KVM_REQ_APICV_UPDATE, vcpu);
+		}
 	} else
 		static_branch_inc(&kvm_has_noapic_vcpu);