[PATCH v2 3/7] x86/kvm/hyper-v: Introduce nested_get_evmcs_version() helper

Vitaly Kuznetsov
2018-12-10T17:22:16Z

The upcoming KVM_GET_SUPPORTED_HV_CPUID ioctl will need to return
Enlightened VMCS version in HYPERV_CPUID_NESTED_FEATURES.EAX when
it was enabled.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
arch/x86/include/asm/kvm_host.h | 1 +
arch/x86/kvm/svm.c | 7 +++++++
arch/x86/kvm/vmx.c | 24 +++++++++++++++++-------
3 files changed, 25 insertions(+), 7 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index e1a40e649cdc..184669d48d80 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1185,6 +1185,7 @@ struct kvm_x86_ops {

int (*nested_enable_evmcs)(struct kvm_vcpu *vcpu,
uint16_t *vmcs_version);
+ uint16_t (*nested_get_evmcs_version)(struct kvm_vcpu *vcpu);
};

struct kvm_arch_async_pf {
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 0e21ccc46792..472f950ccab7 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -7037,6 +7037,12 @@ static int svm_unregister_enc_region(struct kvm *kvm,
return ret;
}

+static uint16_t nested_get_evmcs_version(struct kvm_vcpu *vcpu)
+{
+ /* Not supported */
+ return 0;
+}
+
static int nested_enable_evmcs(struct kvm_vcpu *vcpu,
uint16_t *vmcs_version)
{
@@ -7175,6 +7181,7 @@ static struct kvm_x86_ops svm_x86_ops __ro_after_init = {
.mem_enc_unreg_region = svm_unregister_enc_region,

.nested_enable_evmcs = nested_enable_evmcs,
+ .nested_get_evmcs_version = nested_get_evmcs_version,
};

static int __init svm_init(void)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 4555077d69ce..f5d865e88095 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -1605,6 +1605,21 @@ static inline void evmcs_sanitize_exec_ctrls(struct vmcs_config *vmcs_conf) {}
static inline void evmcs_touch_msr_bitmap(void) {}
#endif /* IS_ENABLED(CONFIG_HYPERV) */

+static 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
+ * maximum supported version. KVM supports versions from 1 to
+ * KVM_EVMCS_VERSION.
+ */
+ if (vmx->nested.enlightened_vmcs_enabled)
+ return (KVM_EVMCS_VERSION << 8) | 1;
+
+ return 0;
+}
+
static int nested_enable_evmcs(struct kvm_vcpu *vcpu,
uint16_t *vmcs_version)
{
@@ -1616,14 +1631,8 @@ static int nested_enable_evmcs(struct kvm_vcpu *vcpu,

vmx->nested.enlightened_vmcs_enabled = true;

- /*
- * vmcs_version represents the range of supported Enlightened VMCS
- * versions: lower 8 bits is the minimal version, higher 8 bits is the
- * maximum supported version. KVM supports versions from 1 to
- * KVM_EVMCS_VERSION.
- */
if (vmcs_version)
- *vmcs_version = (KVM_EVMCS_VERSION << 8) | 1;
+ *vmcs_version = nested_get_evmcs_version(vcpu);

vmx->nested.msrs.pinbased_ctls_high &= ~EVMCS1_UNSUPPORTED_PINCTRL;
vmx->nested.msrs.entry_ctls_high &= ~EVMCS1_UNSUPPORTED_VMENTRY_CTRL;
@@ -15107,6 +15116,7 @@ static struct kvm_x86_ops vmx_x86_ops __ro_after_init = {
.enable_smi_window = enable_smi_window,

.nested_enable_evmcs = nested_enable_evmcs,
+ .nested_get_evmcs_version = nested_get_evmcs_version,
};

static void vmx_cleanup_l1d_flush(void)
--
2.19.2