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

Pull kvm fixes from Paolo Bonzini:
 "Miscellaneous bugfixes, plus a small patchlet related to Spectre v2"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  kvmclock: fix TSC calibration for nested guests
  KVM: VMX: Mark VMXArea with revision_id of physical CPU even when eVMCS enabled
  KVM: irqfd: fix race between EPOLLHUP and irq_bypass_register_consumer
  KVM/Eventfd: Avoid crash when assign and deassign specific eventfd in parallel.
  x86/kvmclock: set pvti_cpu0_va after enabling kvmclock
  x86/kvm/Kconfig: Ensure CRYPTO_DEV_CCP_DD state at minimum matches KVM_AMD
  kvm: nVMX: Restore exit qual for VM-entry failure due to MSR loading
  x86/kvm/vmx: don't read current->thread.{fs,gs}base of legacy tasks
  KVM: VMX: support MSR_IA32_ARCH_CAPABILITIES as a feature MSR

5 files changed, 63 insertions, 33 deletions

diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c
index bf8d1eb7fca3..3b8e7c13c614 100644
--- a/arch/x86/kernel/kvmclock.c
+++ b/arch/x86/kernel/kvmclock.c
@@ -138,6 +138,7 @@ static unsigned long kvm_get_tsc_khz(void)
         src = &hv_clock[cpu].pvti;
         tsc_khz = pvclock_tsc_khz(src);
         put_cpu();
+        setup_force_cpu_cap(X86_FEATURE_TSC_KNOWN_FREQ);
         return tsc_khz;
 }
 
@@ -319,6 +320,8 @@ void __init kvmclock_init(void)
         printk(KERN_INFO "kvm-clock: Using msrs %x and %x",
                 msr_kvm_system_time, msr_kvm_wall_clock);
 
+        pvclock_set_pvti_cpu0_va(hv_clock);
+
         if (kvm_para_has_feature(KVM_FEATURE_CLOCKSOURCE_STABLE_BIT))
                 pvclock_set_flags(PVCLOCK_TSC_STABLE_BIT);
 
@@ -366,14 +369,11 @@ int __init kvm_setup_vsyscall_timeinfo(void)
         vcpu_time = &hv_clock[cpu].pvti;
         flags = pvclock_read_flags(vcpu_time);
 
-        if (!(flags & PVCLOCK_TSC_STABLE_BIT)) {
-                put_cpu();
-                return 1;
-        }
-
-        pvclock_set_pvti_cpu0_va(hv_clock);
         put_cpu();
 
+        if (!(flags & PVCLOCK_TSC_STABLE_BIT))
+                return 1;
+
         kvm_clock.archdata.vclock_mode = VCLOCK_PVCLOCK;
 #endif
         return 0;
diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig
index 92fd433c50b9..1bbec387d289 100644
--- a/arch/x86/kvm/Kconfig
+++ b/arch/x86/kvm/Kconfig
@@ -85,7 +85,7 @@ config KVM_AMD_SEV
         def_bool y
         bool "AMD Secure Encrypted Virtualization (SEV) support"
         depends on KVM_AMD && X86_64
-        depends on CRYPTO_DEV_CCP && CRYPTO_DEV_CCP_DD && CRYPTO_DEV_SP_PSP
+        depends on CRYPTO_DEV_SP_PSP && !(KVM_AMD=y && CRYPTO_DEV_CCP_DD=m)
         ---help---
         Provides support for launching Encrypted VMs on AMD processors.
 
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 1689f433f3a0..e30da9a2430c 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2571,6 +2571,7 @@ static void vmx_save_host_state(struct kvm_vcpu *vcpu)
         struct vcpu_vmx *vmx = to_vmx(vcpu);
 #ifdef CONFIG_X86_64
         int cpu = raw_smp_processor_id();
+        unsigned long fs_base, kernel_gs_base;
 #endif
         int i;
 
@@ -2586,12 +2587,20 @@ static void vmx_save_host_state(struct kvm_vcpu *vcpu)
         vmx->host_state.gs_ldt_reload_needed = vmx->host_state.ldt_sel;
 
 #ifdef CONFIG_X86_64
-        save_fsgs_for_kvm();
-        vmx->host_state.fs_sel = current->thread.fsindex;
-        vmx->host_state.gs_sel = current->thread.gsindex;
-#else
-        savesegment(fs, vmx->host_state.fs_sel);
-        savesegment(gs, vmx->host_state.gs_sel);
+        if (likely(is_64bit_mm(current->mm))) {
+                save_fsgs_for_kvm();
+                vmx->host_state.fs_sel = current->thread.fsindex;
+                vmx->host_state.gs_sel = current->thread.gsindex;
+                fs_base = current->thread.fsbase;
+                kernel_gs_base = current->thread.gsbase;
+        } else {
+#endif
+                savesegment(fs, vmx->host_state.fs_sel);
+                savesegment(gs, vmx->host_state.gs_sel);
+#ifdef CONFIG_X86_64
+                fs_base = read_msr(MSR_FS_BASE);
+                kernel_gs_base = read_msr(MSR_KERNEL_GS_BASE);
+        }
 #endif
         if (!(vmx->host_state.fs_sel & 7)) {
                 vmcs_write16(HOST_FS_SELECTOR, vmx->host_state.fs_sel);
@@ -2611,10 +2620,10 @@ static void vmx_save_host_state(struct kvm_vcpu *vcpu)
         savesegment(ds, vmx->host_state.ds_sel);
         savesegment(es, vmx->host_state.es_sel);
 
-        vmcs_writel(HOST_FS_BASE, current->thread.fsbase);
+        vmcs_writel(HOST_FS_BASE, fs_base);
         vmcs_writel(HOST_GS_BASE, cpu_kernelmode_gs_base(cpu));
 
-        vmx->msr_host_kernel_gs_base = current->thread.gsbase;
+        vmx->msr_host_kernel_gs_base = kernel_gs_base;
         if (is_long_mode(&vmx->vcpu))
                 wrmsrl(MSR_KERNEL_GS_BASE, vmx->msr_guest_kernel_gs_base);
 #else
@@ -4322,11 +4331,7 @@ static __init int setup_vmcs_config(struct vmcs_config *vmcs_conf)
         vmcs_conf->order = get_order(vmcs_conf->size);
         vmcs_conf->basic_cap = vmx_msr_high & ~0x1fff;
 
-        /* KVM supports Enlightened VMCS v1 only */
-        if (static_branch_unlikely(&enable_evmcs))
-                vmcs_conf->revision_id = KVM_EVMCS_VERSION;
-        else
-                vmcs_conf->revision_id = vmx_msr_low;
+        vmcs_conf->revision_id = vmx_msr_low;
 
         vmcs_conf->pin_based_exec_ctrl = _pin_based_exec_control;
         vmcs_conf->cpu_based_exec_ctrl = _cpu_based_exec_control;
@@ -4396,7 +4401,13 @@ static struct vmcs *alloc_vmcs_cpu(int cpu)
                 return NULL;
         vmcs = page_address(pages);
         memset(vmcs, 0, vmcs_config.size);
-        vmcs->revision_id = vmcs_config.revision_id; /* vmcs revision id */
+
+        /* KVM supports Enlightened VMCS v1 only */
+        if (static_branch_unlikely(&enable_evmcs))
+                vmcs->revision_id = KVM_EVMCS_VERSION;
+        else
+                vmcs->revision_id = vmcs_config.revision_id;
+
         return vmcs;
 }
 
@@ -4564,6 +4575,19 @@ static __init int alloc_kvm_area(void)
                         return -ENOMEM;
                 }
 
+                /*
+                 * When eVMCS is enabled, alloc_vmcs_cpu() sets
+                 * vmcs->revision_id to KVM_EVMCS_VERSION instead of
+                 * revision_id reported by MSR_IA32_VMX_BASIC.
+                 *
+                 * However, even though not explictly documented by
+                 * TLFS, VMXArea passed as VMXON argument should
+                 * still be marked with revision_id reported by
+                 * physical CPU.
+                 */
+                if (static_branch_unlikely(&enable_evmcs))
+                        vmcs->revision_id = vmcs_config.revision_id;
+
                 per_cpu(vmxarea, cpu) = vmcs;
         }
         return 0;
@@ -11753,7 +11777,6 @@ static int enter_vmx_non_root_mode(struct kvm_vcpu *vcpu)
 {
         struct vcpu_vmx *vmx = to_vmx(vcpu);
         struct vmcs12 *vmcs12 = get_vmcs12(vcpu);
-        u32 msr_entry_idx;
         u32 exit_qual;
         int r;
 
@@ -11775,10 +11798,10 @@ static int enter_vmx_non_root_mode(struct kvm_vcpu *vcpu)
         nested_get_vmcs12_pages(vcpu, vmcs12);
 
         r = EXIT_REASON_MSR_LOAD_FAIL;
-        msr_entry_idx = nested_vmx_load_msr(vcpu,
-                                            vmcs12->vm_entry_msr_load_addr,
-                                            vmcs12->vm_entry_msr_load_count);
-        if (msr_entry_idx)
+        exit_qual = nested_vmx_load_msr(vcpu,
+                                        vmcs12->vm_entry_msr_load_addr,
+                                        vmcs12->vm_entry_msr_load_count);
+        if (exit_qual)
                 goto fail;
 
         /*
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 0046aa70205a..2b812b3c5088 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1097,6 +1097,7 @@ static u32 msr_based_features[] = {
 
         MSR_F10H_DECFG,
         MSR_IA32_UCODE_REV,
+        MSR_IA32_ARCH_CAPABILITIES,
 };
 
 static unsigned int num_msr_based_features;
@@ -1105,7 +1106,8 @@ static int kvm_get_msr_feature(struct kvm_msr_entry *msr)
 {
         switch (msr->index) {
         case MSR_IA32_UCODE_REV:
-                rdmsrl(msr->index, msr->data);
+        case MSR_IA32_ARCH_CAPABILITIES:
+                rdmsrl_safe(msr->index, &msr->data);
                 break;
         default:
                 if (kvm_x86_ops->get_msr_feature(msr))
diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c
index 90d30fbe95ae..b20b751286fc 100644
--- a/virt/kvm/eventfd.c
+++ b/virt/kvm/eventfd.c
@@ -119,8 +119,12 @@ irqfd_shutdown(struct work_struct *work)
 {
         struct kvm_kernel_irqfd *irqfd =
                 container_of(work, struct kvm_kernel_irqfd, shutdown);
+        struct kvm *kvm = irqfd->kvm;
         u64 cnt;
 
+        /* Make sure irqfd has been initalized in assign path. */
+        synchronize_srcu(&kvm->irq_srcu);
+
         /*
          * Synchronize with the wait-queue and unhook ourselves to prevent
          * further events.
@@ -387,7 +391,6 @@ kvm_irqfd_assign(struct kvm *kvm, struct kvm_irqfd *args)
 
         idx = srcu_read_lock(&kvm->irq_srcu);
         irqfd_update(kvm, irqfd);
-        srcu_read_unlock(&kvm->irq_srcu, idx);
 
         list_add_tail(&irqfd->list, &kvm->irqfds.items);
 
@@ -402,11 +405,6 @@ kvm_irqfd_assign(struct kvm *kvm, struct kvm_irqfd *args)
         if (events & EPOLLIN)
                 schedule_work(&irqfd->inject);
 
-        /*
-         * do not drop the file until the irqfd is fully initialized, otherwise
-         * we might race against the EPOLLHUP
-         */
-        fdput(f);
 #ifdef CONFIG_HAVE_KVM_IRQ_BYPASS
         if (kvm_arch_has_irq_bypass()) {
                 irqfd->consumer.token = (void *)irqfd->eventfd;
@@ -421,6 +419,13 @@ kvm_irqfd_assign(struct kvm *kvm, struct kvm_irqfd *args)
         }
 #endif
 
+        srcu_read_unlock(&kvm->irq_srcu, idx);
+
+        /*
+         * do not drop the file until the irqfd is fully initialized, otherwise
+         * we might race against the EPOLLHUP
+         */
+        fdput(f);
         return 0;
 
 fail: