Commit c21d54f0 authored by Vitaly Kuznetsov's avatar Vitaly Kuznetsov Committed by Paolo Bonzini

KVM: x86: hyper-v: allow KVM_GET_SUPPORTED_HV_CPUID as a system ioctl

KVM_GET_SUPPORTED_HV_CPUID is a vCPU ioctl but its output is now
independent from vCPU and in some cases VMMs may want to use it as a system
ioctl instead. In particular, QEMU doesn CPU feature expansion before any
vCPU gets created so KVM_GET_SUPPORTED_HV_CPUID can't be used.

Convert KVM_GET_SUPPORTED_HV_CPUID to 'dual' system/vCPU ioctl with the
same meaning.
Signed-off-by: default avatarVitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20200929150944.1235688-2-vkuznets@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent b59e00dd
......@@ -4455,9 +4455,9 @@ that KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 is present.
4.118 KVM_GET_SUPPORTED_HV_CPUID
--------------------------------
:Capability: KVM_CAP_HYPERV_CPUID
:Capability: KVM_CAP_HYPERV_CPUID (vcpu), KVM_CAP_SYS_HYPERV_CPUID (system)
:Architectures: x86
:Type: vcpu ioctl
:Type: system ioctl, vcpu ioctl
:Parameters: struct kvm_cpuid2 (in/out)
:Returns: 0 on success, -1 on error
......@@ -4502,9 +4502,6 @@ Currently, the following list of CPUID leaves are returned:
- HYPERV_CPUID_SYNDBG_INTERFACE
- HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES
HYPERV_CPUID_NESTED_FEATURES leaf is only exposed when Enlightened VMCS was
enabled on the corresponding vCPU (KVM_CAP_HYPERV_ENLIGHTENED_VMCS).
Userspace invokes KVM_GET_SUPPORTED_HV_CPUID by passing a kvm_cpuid2 structure
with the 'nent' field indicating the number of entries in the variable-size
array 'entries'. If the number of entries is too low to describe all Hyper-V
......@@ -4515,6 +4512,15 @@ number of valid entries in the 'entries' array, which is then filled.
'index' and 'flags' fields in 'struct kvm_cpuid_entry2' are currently reserved,
userspace should not expect to get any particular value there.
Note, vcpu version of KVM_GET_SUPPORTED_HV_CPUID is currently deprecated. Unlike
system ioctl which exposes all supported feature bits unconditionally, vcpu
version has the following quirks:
- HYPERV_CPUID_NESTED_FEATURES leaf and HV_X64_ENLIGHTENED_VMCS_RECOMMENDED
feature bit are only exposed when Enlightened VMCS was previously enabled
on the corresponding vCPU (KVM_CAP_HYPERV_ENLIGHTENED_VMCS).
- HV_STIMER_DIRECT_MODE_AVAILABLE bit is only exposed with in-kernel LAPIC.
(presumes KVM_CREATE_IRQCHIP has already been called).
4.119 KVM_ARM_VCPU_FINALIZE
---------------------------
......
......@@ -1951,8 +1951,8 @@ int kvm_vm_ioctl_hv_eventfd(struct kvm *kvm, struct kvm_hyperv_eventfd *args)
return kvm_hv_eventfd_assign(kvm, args->conn_id, args->fd);
}
int kvm_vcpu_ioctl_get_hv_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid2 *cpuid,
struct kvm_cpuid_entry2 __user *entries)
int kvm_get_hv_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid2 *cpuid,
struct kvm_cpuid_entry2 __user *entries)
{
uint16_t evmcs_ver = 0;
struct kvm_cpuid_entry2 cpuid_entries[] = {
......@@ -2037,7 +2037,7 @@ int kvm_vcpu_ioctl_get_hv_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid2 *cpuid,
* Direct Synthetic timers only make sense with in-kernel
* LAPIC
*/
if (lapic_in_kernel(vcpu))
if (!vcpu || lapic_in_kernel(vcpu))
ent->edx |= HV_STIMER_DIRECT_MODE_AVAILABLE;
break;
......
......@@ -126,7 +126,7 @@ void kvm_hv_setup_tsc_page(struct kvm *kvm,
void kvm_hv_init_vm(struct kvm *kvm);
void kvm_hv_destroy_vm(struct kvm *kvm);
int kvm_vm_ioctl_hv_eventfd(struct kvm *kvm, struct kvm_hyperv_eventfd *args);
int kvm_vcpu_ioctl_get_hv_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid2 *cpuid,
struct kvm_cpuid_entry2 __user *entries);
int kvm_get_hv_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid2 *cpuid,
struct kvm_cpuid_entry2 __user *entries);
#endif
......@@ -326,7 +326,6 @@ bool nested_enlightened_vmentry(struct kvm_vcpu *vcpu, u64 *evmcs_gpa)
uint16_t nested_get_evmcs_version(struct kvm_vcpu *vcpu)
{
struct vcpu_vmx *vmx = to_vmx(vcpu);
/*
* vmcs_version represents the range of supported Enlightened VMCS
* versions: lower 8 bits is the minimal version, higher 8 bits is the
......@@ -334,7 +333,7 @@ uint16_t nested_get_evmcs_version(struct kvm_vcpu *vcpu)
* KVM_EVMCS_VERSION.
*/
if (kvm_cpu_cap_get(X86_FEATURE_VMX) &&
vmx->nested.enlightened_vmcs_enabled)
(!vcpu || to_vmx(vcpu)->nested.enlightened_vmcs_enabled))
return (KVM_EVMCS_VERSION << 8) | 1;
return 0;
......
......@@ -3677,6 +3677,27 @@ static inline bool kvm_can_mwait_in_guest(void)
boot_cpu_has(X86_FEATURE_ARAT);
}
static int kvm_ioctl_get_supported_hv_cpuid(struct kvm_vcpu *vcpu,
struct kvm_cpuid2 __user *cpuid_arg)
{
struct kvm_cpuid2 cpuid;
int r;
r = -EFAULT;
if (copy_from_user(&cpuid, cpuid_arg, sizeof(cpuid)))
return r;
r = kvm_get_hv_cpuid(vcpu, &cpuid, cpuid_arg->entries);
if (r)
return r;
r = -EFAULT;
if (copy_to_user(cpuid_arg, &cpuid, sizeof(cpuid)))
return r;
return 0;
}
int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
{
int r = 0;
......@@ -3713,6 +3734,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
case KVM_CAP_HYPERV_TLBFLUSH:
case KVM_CAP_HYPERV_SEND_IPI:
case KVM_CAP_HYPERV_CPUID:
case KVM_CAP_SYS_HYPERV_CPUID:
case KVM_CAP_PCI_SEGMENT:
case KVM_CAP_DEBUGREGS:
case KVM_CAP_X86_ROBUST_SINGLESTEP:
......@@ -3898,6 +3920,9 @@ long kvm_arch_dev_ioctl(struct file *filp,
case KVM_GET_MSRS:
r = msr_io(NULL, argp, do_get_msr_feature, 1);
break;
case KVM_GET_SUPPORTED_HV_CPUID:
r = kvm_ioctl_get_supported_hv_cpuid(NULL, argp);
break;
default:
r = -EINVAL;
break;
......@@ -4974,25 +4999,9 @@ long kvm_arch_vcpu_ioctl(struct file *filp,
srcu_read_unlock(&vcpu->kvm->srcu, idx);
break;
}
case KVM_GET_SUPPORTED_HV_CPUID: {
struct kvm_cpuid2 __user *cpuid_arg = argp;
struct kvm_cpuid2 cpuid;
r = -EFAULT;
if (copy_from_user(&cpuid, cpuid_arg, sizeof(cpuid)))
goto out;
r = kvm_vcpu_ioctl_get_hv_cpuid(vcpu, &cpuid,
cpuid_arg->entries);
if (r)
goto out;
r = -EFAULT;
if (copy_to_user(cpuid_arg, &cpuid, sizeof(cpuid)))
goto out;
r = 0;
case KVM_GET_SUPPORTED_HV_CPUID:
r = kvm_ioctl_get_supported_hv_cpuid(vcpu, argp);
break;
}
default:
r = -EINVAL;
}
......
......@@ -1053,6 +1053,7 @@ struct kvm_ppc_resize_hpt {
#define KVM_CAP_X86_USER_SPACE_MSR 188
#define KVM_CAP_X86_MSR_FILTER 189
#define KVM_CAP_ENFORCE_PV_FEATURE_CPUID 190
#define KVM_CAP_SYS_HYPERV_CPUID 191
#ifdef KVM_CAP_IRQ_ROUTING
......@@ -1511,7 +1512,7 @@ struct kvm_enc_region {
/* Available with KVM_CAP_MANUAL_DIRTY_LOG_PROTECT_2 */
#define KVM_CLEAR_DIRTY_LOG _IOWR(KVMIO, 0xc0, struct kvm_clear_dirty_log)
/* Available with KVM_CAP_HYPERV_CPUID */
/* Available with KVM_CAP_HYPERV_CPUID (vcpu) / KVM_CAP_SYS_HYPERV_CPUID (system) */
#define KVM_GET_SUPPORTED_HV_CPUID _IOWR(KVMIO, 0xc1, struct kvm_cpuid2)
/* Available with KVM_CAP_ARM_SVE */
......
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