diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index cded99561adf..e328caa35d6c 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -6950,3 +6950,22 @@ guest according to the bits Hyper-V CPUID feature leaves. Otherwise, all currently implmented Hyper-V features are provided unconditionally when Hyper-V identification is set in the HYPERV_CPUID_INTERFACE (0x40000001) leaf. + +8.34 KVM_CAP_EXIT_HYPERCALL +--------------------------- + +:Capability: KVM_CAP_EXIT_HYPERCALL +:Architectures: x86 +:Type: vm + +This capability, if enabled, will cause KVM to exit to userspace +with KVM_EXIT_HYPERCALL exit reason to process some hypercalls. + +Calling KVM_CHECK_EXTENSION for this capability will return a bitmask +of hypercalls that can be configured to exit to userspace. +Right now, the only such hypercall is KVM_HC_MAP_GPA_RANGE. + +The argument to KVM_ENABLE_CAP is also a bitmask, and must be a subset +of the result of KVM_CHECK_EXTENSION. KVM will forward to userspace +the hypercalls whose corresponding bit is in the argument, and return +ENOSYS for the others. diff --git a/Documentation/virt/kvm/cpuid.rst b/Documentation/virt/kvm/cpuid.rst index cf62162d4be2..bda3e3e737d7 100644 --- a/Documentation/virt/kvm/cpuid.rst +++ b/Documentation/virt/kvm/cpuid.rst @@ -96,6 +96,13 @@ KVM_FEATURE_MSI_EXT_DEST_ID 15 guest checks this feature bit before using extended destination ID bits in MSI address bits 11-5. +KVM_FEATURE_HC_MAP_GPA_RANGE 16 guest checks this feature bit before + using the map gpa range hypercall + to notify the page state change + +KVM_FEATURE_MIGRATION_CONTROL 17 guest checks this feature bit before + using MSR_KVM_MIGRATION_CONTROL + KVM_FEATURE_CLOCKSOURCE_STABLE_BIT 24 host will warn if no guest-side per-cpu warps are expected in kvmclock diff --git a/Documentation/virt/kvm/hypercalls.rst b/Documentation/virt/kvm/hypercalls.rst index ed4fddd364ea..e56fa8b9cfca 100644 --- a/Documentation/virt/kvm/hypercalls.rst +++ b/Documentation/virt/kvm/hypercalls.rst @@ -169,3 +169,24 @@ a0: destination APIC ID :Usage example: When sending a call-function IPI-many to vCPUs, yield if any of the IPI target vCPUs was preempted. + +8. KVM_HC_MAP_GPA_RANGE +------------------------- +:Architecture: x86 +:Status: active +:Purpose: Request KVM to map a GPA range with the specified attributes. + +a0: the guest physical address of the start page +a1: the number of (4kb) pages (must be contiguous in GPA space) +a2: attributes + + Where 'attributes' : + * bits 3:0 - preferred page size encoding 0 = 4kb, 1 = 2mb, 2 = 1gb, etc... + * bit 4 - plaintext = 0, encrypted = 1 + * bits 63:5 - reserved (must be zero) + +**Implementation note**: this hypercall is implemented in userspace via +the KVM_CAP_EXIT_HYPERCALL capability. Userspace must enable that capability +before advertising KVM_FEATURE_HC_MAP_GPA_RANGE in the guest CPUID. In +addition, if the guest supports KVM_FEATURE_MIGRATION_CONTROL, userspace +must also set up an MSR filter to process writes to MSR_KVM_MIGRATION_CONTROL. diff --git a/Documentation/virt/kvm/msr.rst b/Documentation/virt/kvm/msr.rst index e37a14c323d2..9315fc385fb0 100644 --- a/Documentation/virt/kvm/msr.rst +++ b/Documentation/virt/kvm/msr.rst @@ -376,3 +376,16 @@ data: write '1' to bit 0 of the MSR, this causes the host to re-scan its queue and check if there are more notifications pending. The MSR is available if KVM_FEATURE_ASYNC_PF_INT is present in CPUID. + +MSR_KVM_MIGRATION_CONTROL: + 0x4b564d08 + +data: + This MSR is available if KVM_FEATURE_MIGRATION_CONTROL is present in + CPUID. Bit 0 represents whether live migration of the guest is allowed. + + When a guest is started, bit 0 will be 0 if the guest has encrypted + memory and 1 if the guest does not have encrypted memory. If the + guest is communicating page encryption status to the host using the + ``KVM_HC_MAP_GPA_RANGE`` hypercall, it can set bit 0 in this MSR to + allow live migration of the guest. diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index a0c29e29dd48..e11d64aa0bcd 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1087,6 +1087,8 @@ struct kvm_arch { u32 user_space_msr_mask; struct kvm_x86_msr_filter __rcu *msr_filter; + u32 hypercall_exit_enabled; + /* Guest can access the SGX PROVISIONKEY. */ bool sgx_provisioning_allowed; diff --git a/arch/x86/include/uapi/asm/kvm_para.h b/arch/x86/include/uapi/asm/kvm_para.h index 950afebfba88..5146bbab84d4 100644 --- a/arch/x86/include/uapi/asm/kvm_para.h +++ b/arch/x86/include/uapi/asm/kvm_para.h @@ -33,6 +33,8 @@ #define KVM_FEATURE_PV_SCHED_YIELD 13 #define KVM_FEATURE_ASYNC_PF_INT 14 #define KVM_FEATURE_MSI_EXT_DEST_ID 15 +#define KVM_FEATURE_HC_MAP_GPA_RANGE 16 +#define KVM_FEATURE_MIGRATION_CONTROL 17 #define KVM_HINTS_REALTIME 0 @@ -54,6 +56,7 @@ #define MSR_KVM_POLL_CONTROL 0x4b564d05 #define MSR_KVM_ASYNC_PF_INT 0x4b564d06 #define MSR_KVM_ASYNC_PF_ACK 0x4b564d07 +#define MSR_KVM_MIGRATION_CONTROL 0x4b564d08 struct kvm_steal_time { __u64 steal; @@ -90,6 +93,16 @@ struct kvm_clock_pairing { /* MSR_KVM_ASYNC_PF_INT */ #define KVM_ASYNC_PF_VEC_MASK GENMASK(7, 0) +/* MSR_KVM_MIGRATION_CONTROL */ +#define KVM_MIGRATION_READY (1 << 0) + +/* KVM_HC_MAP_GPA_RANGE */ +#define KVM_MAP_GPA_RANGE_PAGE_SZ_4K 0 +#define KVM_MAP_GPA_RANGE_PAGE_SZ_2M (1 << 0) +#define KVM_MAP_GPA_RANGE_PAGE_SZ_1G (1 << 1) +#define KVM_MAP_GPA_RANGE_ENC_STAT(n) (n << 4) +#define KVM_MAP_GPA_RANGE_ENCRYPTED KVM_MAP_GPA_RANGE_ENC_STAT(1) +#define KVM_MAP_GPA_RANGE_DECRYPTED KVM_MAP_GPA_RANGE_ENC_STAT(0) /* Operations for KVM_HC_MMU_OP */ #define KVM_MMU_OP_WRITE_PTE 1 diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index ceb60f64085c..8b898ec8d349 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -103,6 +103,8 @@ static u64 __read_mostly efer_reserved_bits = ~((u64)EFER_SCE); static u64 __read_mostly cr4_reserved_bits = CR4_RESERVED_BITS; +#define KVM_EXIT_HYPERCALL_VALID_MASK (1 << KVM_HC_MAP_GPA_RANGE) + #define KVM_X2APIC_API_VALID_FLAGS (KVM_X2APIC_API_USE_32BIT_IDS | \ KVM_X2APIC_API_DISABLE_BROADCAST_QUIRK) @@ -3996,6 +3998,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) case KVM_CAP_SREGS2: r = 1; break; + case KVM_CAP_EXIT_HYPERCALL: + r = KVM_EXIT_HYPERCALL_VALID_MASK; + break; case KVM_CAP_SET_GUEST_DEBUG2: return KVM_GUESTDBG_VALID_MASK; #ifdef CONFIG_KVM_XEN @@ -5622,6 +5627,14 @@ split_irqchip_unlock: if (kvm_x86_ops.vm_copy_enc_context_from) r = kvm_x86_ops.vm_copy_enc_context_from(kvm, cap->args[0]); return r; + case KVM_CAP_EXIT_HYPERCALL: + if (cap->args[0] & ~KVM_EXIT_HYPERCALL_VALID_MASK) { + r = -EINVAL; + break; + } + kvm->arch.hypercall_exit_enabled = cap->args[0]; + r = 0; + break; default: r = -EINVAL; break; @@ -8548,6 +8561,17 @@ no_yield: return; } +static int complete_hypercall_exit(struct kvm_vcpu *vcpu) +{ + u64 ret = vcpu->run->hypercall.ret; + + if (!is_64_bit_mode(vcpu)) + ret = (u32)ret; + kvm_rax_write(vcpu, ret); + ++vcpu->stat.hypercalls; + return kvm_skip_emulated_instruction(vcpu); +} + int kvm_emulate_hypercall(struct kvm_vcpu *vcpu) { unsigned long nr, a0, a1, a2, a3, ret; @@ -8613,6 +8637,28 @@ int kvm_emulate_hypercall(struct kvm_vcpu *vcpu) kvm_sched_yield(vcpu, a0); ret = 0; break; + case KVM_HC_MAP_GPA_RANGE: { + u64 gpa = a0, npages = a1, attrs = a2; + + ret = -KVM_ENOSYS; + if (!(vcpu->kvm->arch.hypercall_exit_enabled & (1 << KVM_HC_MAP_GPA_RANGE))) + break; + + if (!PAGE_ALIGNED(gpa) || !npages || + gpa_to_gfn(gpa) + npages <= gpa_to_gfn(gpa)) { + ret = -KVM_EINVAL; + break; + } + + vcpu->run->exit_reason = KVM_EXIT_HYPERCALL; + vcpu->run->hypercall.nr = KVM_HC_MAP_GPA_RANGE; + vcpu->run->hypercall.args[0] = gpa; + vcpu->run->hypercall.args[1] = npages; + vcpu->run->hypercall.args[2] = attrs; + vcpu->run->hypercall.longmode = op_64_bit; + vcpu->arch.complete_userspace_io = complete_hypercall_exit; + return 0; + } default: ret = -KVM_ENOSYS; break; diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 90d44138dbfb..9febe1412f7a 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -1085,6 +1085,7 @@ struct kvm_ppc_resize_hpt { #define KVM_CAP_PTP_KVM 198 #define KVM_CAP_HYPERV_ENFORCE_CPUID 199 #define KVM_CAP_SREGS2 200 +#define KVM_CAP_EXIT_HYPERCALL 201 #ifdef KVM_CAP_IRQ_ROUTING diff --git a/include/uapi/linux/kvm_para.h b/include/uapi/linux/kvm_para.h index 8b86609849b9..960c7e93d1a9 100644 --- a/include/uapi/linux/kvm_para.h +++ b/include/uapi/linux/kvm_para.h @@ -29,6 +29,7 @@ #define KVM_HC_CLOCK_PAIRING 9 #define KVM_HC_SEND_IPI 10 #define KVM_HC_SCHED_YIELD 11 +#define KVM_HC_MAP_GPA_RANGE 12 /* * hypercalls use architecture specific