[PATCH RFC v1 0/5] KVM: VMX: Support TscScaling and EnclsExitingBitmap whith eVMCS

[PATCH RFC v1 0/5] KVM: VMX: Support TscScaling and EnclsExitingBitmap whith eVMCS

[Vitaly Kuznetsov]

Enlightened VMCS v1 definition was updates to include fields for the
following features:
    - PerfGlobalCtrl
    - EnclsExitingBitmap
    - TSC scaling
    - GuestLbrCtl
    - CET
    - SSP

Add support for EnclsExitingBitmap and TSC scaling to KVM. PerfGlobalCtrl 
doesn't work correctly with Win11, don't enable it yet. SSP, CET and 
GuestLbrCtl are not currently supported by KVM.

RFC part: the change dropping SECONDARY_EXEC_TSC_SCALING from 
EVMCS1_UNSUPPORTED_2NDEXEC likely breaks migration for Hyper-V on KVM: in
case guest which started on a 'fixed' KVM and uses TSC multiplier feature
gets migrated to an older 'unfixed' KVM the feature will become unusable.
Unfortunately, eVMCS's version is still '1' so we probably need a new
CAP in KVM to make TSC scaling an explicit opt-in.

Vitaly Kuznetsov (5):
  x86/hyperv: Fix 'struct hv_enlightened_vmcs' definition
  x86/hyperv: Update 'struct hv_enlightened_vmcs' definition
  KVM: VMX: Define VMCS-to-EVMCS conversion for the new fields
  KVM: nVMX: Support several new fields in eVMCSv1
  KVM: VMX: Support TSC scaling with enlightened VMCS

 arch/x86/include/asm/hyperv-tlfs.h | 19 ++++++++++++++----
 arch/x86/kvm/vmx/evmcs.c           | 26 +++++++++++++++++++++++++
 arch/x86/kvm/vmx/evmcs.h           | 11 ++++-------
 arch/x86/kvm/vmx/nested.c          | 31 ++++++++++++++++++++++++++++++
 4 files changed, 76 insertions(+), 11 deletions(-)

-- 
2.35.3

[PATCH RFC v1 1/5] x86/hyperv: Fix 'struct hv_enlightened_vmcs' definition

[Vitaly Kuznetsov]

Section 1.9 of TLFS v6.0b says:

"All structures are padded in such a way that fields are aligned
naturally (that is, an 8-byte field is aligned to an offset of 8 bytes
and so on)".

'struct enlightened_vmcs' has a glitch:

...
        struct {
                u32                nested_flush_hypercall:1; /*   836: 0  4 */
                u32                msr_bitmap:1;         /*   836: 1  4 */
                u32                reserved:30;          /*   836: 2  4 */
        } hv_enlightenments_control;                     /*   836     4 */
        u32                        hv_vp_id;             /*   840     4 */
        u64                        hv_vm_id;             /*   844     8 */
        u64                        partition_assist_page; /*   852     8 */
...

And the observed values in 'partition_assist_page' make no sense at
all. Fix the layout by padding the structure properly.

Fixes: 68d1eb72ee99 ("x86/hyper-v: define struct hv_enlightened_vmcs and clean field bits")
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
 arch/x86/include/asm/hyperv-tlfs.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/hyperv-tlfs.h b/arch/x86/include/asm/hyperv-tlfs.h
index 0a9407dc0859..6f0acc45e67a 100644
--- a/arch/x86/include/asm/hyperv-tlfs.h
+++ b/arch/x86/include/asm/hyperv-tlfs.h
@@ -546,7 +546,7 @@ struct hv_enlightened_vmcs {
 	u64 guest_rip;
 
 	u32 hv_clean_fields;
-	u32 hv_padding_32;
+	u32 padding32_1;
 	u32 hv_synthetic_controls;
 	struct {
 		u32 nested_flush_hypercall:1;
@@ -554,7 +554,7 @@ struct hv_enlightened_vmcs {
 		u32 reserved:30;
 	}  __packed hv_enlightenments_control;
 	u32 hv_vp_id;
-
+	u32 padding32_2;
 	u64 hv_vm_id;
 	u64 partition_assist_page;
 	u64 padding64_4[4];
-- 
2.35.3

[PATCH RFC v1 2/5] x86/hyperv: Update 'struct hv_enlightened_vmcs' definition

[Vitaly Kuznetsov]

Updated Hyper-V Enlightened VMCS specification lists several new
fields for the following features:

- PerfGlobalCtrl
- EnclsExitingBitmap
- Tsc Scaling
- GuestLbrCtl
- CET
- SSP

Update the definition.

Note: The latest TLFS is available at
https://docs.microsoft.com/en-us/virtualization/hyper-v-on-windows/tlfs/tlfs

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
 arch/x86/include/asm/hyperv-tlfs.h | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/hyperv-tlfs.h b/arch/x86/include/asm/hyperv-tlfs.h
index 6f0acc45e67a..fd334e8defb7 100644
--- a/arch/x86/include/asm/hyperv-tlfs.h
+++ b/arch/x86/include/asm/hyperv-tlfs.h
@@ -559,9 +559,20 @@ struct hv_enlightened_vmcs {
 	u64 partition_assist_page;
 	u64 padding64_4[4];
 	u64 guest_bndcfgs;
-	u64 padding64_5[7];
+	u64 guest_ia32_perf_global_ctrl;
+	u64 guest_ia32_s_cet;
+	u64 guest_ssp;
+	u64 guest_ia32_int_ssp_table_addr;
+	u64 guest_ia32_lbr_ctl;
+	u64 padding64_5[2];
 	u64 xss_exit_bitmap;
-	u64 padding64_6[7];
+	u64 host_ia32_perf_global_ctrl;
+	u64 encls_exiting_bitmap;
+	u64 tsc_multiplier;
+	u64 host_ia32_s_cet;
+	u64 host_ssp;
+	u64 host_ia32_int_ssp_table_addr;
+	u64 padding64_6;
 } __packed;
 
 #define HV_VMX_ENLIGHTENED_CLEAN_FIELD_NONE			0
-- 
2.35.3

[PATCH RFC v1 3/5] KVM: VMX: Define VMCS-to-EVMCS conversion for the new fields

[Vitaly Kuznetsov]

Enlightened VMCS v1 definition was updated with new fields, support
them in KVM by defining VMCS-to-EVMCS conversion.

Note: SSP, CET and Guest LBR features are not supported by KVM yet and
the corresponding fields are not defined in 'enum vmcs_field', leave
them commented out for now.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
 arch/x86/kvm/vmx/evmcs.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/arch/x86/kvm/vmx/evmcs.c b/arch/x86/kvm/vmx/evmcs.c
index 6a61b1ae7942..8bea5dea0341 100644
--- a/arch/x86/kvm/vmx/evmcs.c
+++ b/arch/x86/kvm/vmx/evmcs.c
@@ -28,6 +28,8 @@ const struct evmcs_field vmcs_field_to_evmcs_1[] = {
 		     HV_VMX_ENLIGHTENED_CLEAN_FIELD_HOST_GRP1),
 	EVMCS1_FIELD(HOST_IA32_EFER, host_ia32_efer,
 		     HV_VMX_ENLIGHTENED_CLEAN_FIELD_HOST_GRP1),
+	EVMCS1_FIELD(HOST_IA32_PERF_GLOBAL_CTRL, host_ia32_perf_global_ctrl,
+		     HV_VMX_ENLIGHTENED_CLEAN_FIELD_HOST_GRP1),
 	EVMCS1_FIELD(HOST_CR0, host_cr0,
 		     HV_VMX_ENLIGHTENED_CLEAN_FIELD_HOST_GRP1),
 	EVMCS1_FIELD(HOST_CR3, host_cr3,
@@ -78,6 +80,8 @@ const struct evmcs_field vmcs_field_to_evmcs_1[] = {
 		     HV_VMX_ENLIGHTENED_CLEAN_FIELD_GUEST_GRP1),
 	EVMCS1_FIELD(GUEST_IA32_EFER, guest_ia32_efer,
 		     HV_VMX_ENLIGHTENED_CLEAN_FIELD_GUEST_GRP1),
+	EVMCS1_FIELD(GUEST_IA32_PERF_GLOBAL_CTRL, guest_ia32_perf_global_ctrl,
+		     HV_VMX_ENLIGHTENED_CLEAN_FIELD_GUEST_GRP1),
 	EVMCS1_FIELD(GUEST_PDPTR0, guest_pdptr0,
 		     HV_VMX_ENLIGHTENED_CLEAN_FIELD_GUEST_GRP1),
 	EVMCS1_FIELD(GUEST_PDPTR1, guest_pdptr1,
@@ -126,6 +130,28 @@ const struct evmcs_field vmcs_field_to_evmcs_1[] = {
 		     HV_VMX_ENLIGHTENED_CLEAN_FIELD_GUEST_GRP1),
 	EVMCS1_FIELD(XSS_EXIT_BITMAP, xss_exit_bitmap,
 		     HV_VMX_ENLIGHTENED_CLEAN_FIELD_CONTROL_GRP2),
+	EVMCS1_FIELD(ENCLS_EXITING_BITMAP, encls_exiting_bitmap,
+		     HV_VMX_ENLIGHTENED_CLEAN_FIELD_CONTROL_GRP2),
+	EVMCS1_FIELD(TSC_MULTIPLIER, tsc_multiplier,
+		     HV_VMX_ENLIGHTENED_CLEAN_FIELD_CONTROL_GRP2),
+	/*
+	 * Not used by KVM:
+	 *
+	 * EVMCS1_FIELD(0x00006828, guest_ia32_s_cet,
+	 *	     HV_VMX_ENLIGHTENED_CLEAN_FIELD_GUEST_GRP1),
+	 * EVMCS1_FIELD(0x0000682A, guest_ssp,
+	 *	     HV_VMX_ENLIGHTENED_CLEAN_FIELD_GUEST_BASIC),
+	 * EVMCS1_FIELD(0x0000682C, guest_ia32_int_ssp_table_addr,
+	 *	     HV_VMX_ENLIGHTENED_CLEAN_FIELD_GUEST_GRP1),
+	 * EVMCS1_FIELD(0x00002816, guest_ia32_lbr_ctl,
+	 *	     HV_VMX_ENLIGHTENED_CLEAN_FIELD_GUEST_GRP1),
+	 * EVMCS1_FIELD(0x00006C18, host_ia32_s_cet,
+	 *	     HV_VMX_ENLIGHTENED_CLEAN_FIELD_HOST_GRP1),
+	 * EVMCS1_FIELD(0x00006C1A, host_ssp,
+	 *	     HV_VMX_ENLIGHTENED_CLEAN_FIELD_HOST_GRP1),
+	 * EVMCS1_FIELD(0x00006C1C, host_ia32_int_ssp_table_addr,
+	 *	     HV_VMX_ENLIGHTENED_CLEAN_FIELD_HOST_GRP1),
+	 */
 
 	/* 64 bit read only */
 	EVMCS1_FIELD(GUEST_PHYSICAL_ADDRESS, guest_physical_address,
-- 
2.35.3

[PATCH RFC v1 4/5] KVM: nVMX: Support several new fields in eVMCSv1

[Vitaly Kuznetsov]

Enlightened VMCS v1 definition was updated with new fields, add
support for them for Hyper-V on KVM.

Note: SSP, CET and Guest LBR features are not supported by KVM yet
and 'struct vmcs12' has no corresponding fields.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
 arch/x86/kvm/vmx/nested.c | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 7d8cd0ebcc75..162f4b4502e1 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -1602,6 +1602,10 @@ static void copy_enlightened_to_vmcs12(struct vcpu_vmx *vmx, u32 hv_clean_fields
 		vmcs12->guest_rflags = evmcs->guest_rflags;
 		vmcs12->guest_interruptibility_info =
 			evmcs->guest_interruptibility_info;
+		/*
+		 * Not present in struct vmcs12:
+		 * vmcs12->guest_ssp = evmcs->guest_ssp;
+		 */
 	}
 
 	if (unlikely(!(hv_clean_fields &
@@ -1648,6 +1652,13 @@ static void copy_enlightened_to_vmcs12(struct vcpu_vmx *vmx, u32 hv_clean_fields
 		vmcs12->host_fs_selector = evmcs->host_fs_selector;
 		vmcs12->host_gs_selector = evmcs->host_gs_selector;
 		vmcs12->host_tr_selector = evmcs->host_tr_selector;
+		vmcs12->host_ia32_perf_global_ctrl = evmcs->host_ia32_perf_global_ctrl;
+		/*
+		 * Not present in struct vmcs12:
+		 * vmcs12->host_ia32_s_cet = evmcs->host_ia32_s_cet;
+		 * vmcs12->host_ssp = evmcs->host_ssp;
+		 * vmcs12->host_ia32_int_ssp_table_addr = evmcs->host_ia32_int_ssp_table_addr;
+		 */
 	}
 
 	if (unlikely(!(hv_clean_fields &
@@ -1715,6 +1726,8 @@ static void copy_enlightened_to_vmcs12(struct vcpu_vmx *vmx, u32 hv_clean_fields
 		vmcs12->tsc_offset = evmcs->tsc_offset;
 		vmcs12->virtual_apic_page_addr = evmcs->virtual_apic_page_addr;
 		vmcs12->xss_exit_bitmap = evmcs->xss_exit_bitmap;
+		vmcs12->encls_exiting_bitmap = evmcs->encls_exiting_bitmap;
+		vmcs12->tsc_multiplier = evmcs->tsc_multiplier;
 	}
 
 	if (unlikely(!(hv_clean_fields &
@@ -1762,6 +1775,13 @@ static void copy_enlightened_to_vmcs12(struct vcpu_vmx *vmx, u32 hv_clean_fields
 		vmcs12->guest_bndcfgs = evmcs->guest_bndcfgs;
 		vmcs12->guest_activity_state = evmcs->guest_activity_state;
 		vmcs12->guest_sysenter_cs = evmcs->guest_sysenter_cs;
+		vmcs12->guest_ia32_perf_global_ctrl = evmcs->guest_ia32_perf_global_ctrl;
+		/*
+		 * Not present in struct vmcs12:
+		 * vmcs12->guest_ia32_s_cet = evmcs->guest_ia32_s_cet;
+		 * vmcs12->guest_ia32_lbr_ctl = evmcs->guest_ia32_lbr_ctl;
+		 * vmcs12->guest_ia32_int_ssp_table_addr = evmcs->guest_ia32_int_ssp_table_addr;
+		 */
 	}
 
 	/*
@@ -1864,12 +1884,23 @@ static void copy_vmcs12_to_enlightened(struct vcpu_vmx *vmx)
 	 * evmcs->vm_exit_msr_store_count = vmcs12->vm_exit_msr_store_count;
 	 * evmcs->vm_exit_msr_load_count = vmcs12->vm_exit_msr_load_count;
 	 * evmcs->vm_entry_msr_load_count = vmcs12->vm_entry_msr_load_count;
+	 * evmcs->guest_ia32_perf_global_ctrl = vmcs12->guest_ia32_perf_global_ctrl;
+	 * evmcs->host_ia32_perf_global_ctrl = vmcs12->host_ia32_perf_global_ctrl;
+	 * evmcs->encls_exiting_bitmap = vmcs12->encls_exiting_bitmap;
+	 * evmcs->tsc_multiplier = vmcs12->tsc_multiplier;
 	 *
 	 * Not present in struct vmcs12:
 	 * evmcs->exit_io_instruction_ecx = vmcs12->exit_io_instruction_ecx;
 	 * evmcs->exit_io_instruction_esi = vmcs12->exit_io_instruction_esi;
 	 * evmcs->exit_io_instruction_edi = vmcs12->exit_io_instruction_edi;
 	 * evmcs->exit_io_instruction_eip = vmcs12->exit_io_instruction_eip;
+	 * evmcs->host_ia32_s_cet = vmcs12->host_ia32_s_cet;
+	 * evmcs->host_ssp = vmcs12->host_ssp;
+	 * evmcs->host_ia32_int_ssp_table_addr = vmcs12->host_ia32_int_ssp_table_addr;
+	 * evmcs->guest_ia32_s_cet = vmcs12->guest_ia32_s_cet;
+	 * evmcs->guest_ia32_lbr_ctl = vmcs12->guest_ia32_lbr_ctl;
+	 * evmcs->guest_ia32_int_ssp_table_addr = vmcs12->guest_ia32_int_ssp_table_addr;
+	 * evmcs->guest_ssp = vmcs12->guest_ssp;
 	 */
 
 	evmcs->guest_es_selector = vmcs12->guest_es_selector;
-- 
2.35.3

[PATCH RFC v1 5/5] KVM: VMX: Support TSC scaling with enlightened VMCS

[Vitaly Kuznetsov]

Enlightened VMCS v1 now includes the required field for TSC scaling
feature so SECONDARY_EXEC_TSC_SCALING can remain unfiltered.

While on it, update the comment why VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL/
VM_ENTRY_LOAD_IA32_PERF_GLOBAL_CTRL are keept filtered out.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
 arch/x86/kvm/vmx/evmcs.h | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/arch/x86/kvm/vmx/evmcs.h b/arch/x86/kvm/vmx/evmcs.h
index f886a8ff0342..ffdf8955c62c 100644
--- a/arch/x86/kvm/vmx/evmcs.h
+++ b/arch/x86/kvm/vmx/evmcs.h
@@ -37,16 +37,14 @@ DECLARE_STATIC_KEY_FALSE(enable_evmcs);
  *	EPTP_LIST_ADDRESS               = 0x00002024,
  *	VMREAD_BITMAP                   = 0x00002026,
  *	VMWRITE_BITMAP                  = 0x00002028,
- *
- *	TSC_MULTIPLIER                  = 0x00002032,
  *	PLE_GAP                         = 0x00004020,
  *	PLE_WINDOW                      = 0x00004022,
  *	VMX_PREEMPTION_TIMER_VALUE      = 0x0000482E,
- *      GUEST_IA32_PERF_GLOBAL_CTRL     = 0x00002808,
- *      HOST_IA32_PERF_GLOBAL_CTRL      = 0x00002c04,
  *
- * Currently unsupported in KVM:
- *	GUEST_IA32_RTIT_CTL		= 0x00002814,
+ *	While GUEST_IA32_PERF_GLOBAL_CTRL and HOST_IA32_PERF_GLOBAL_CTRL
+ *	are present in eVMCSv1, Windows 11 still has issues booting when
+ *	VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL/VM_ENTRY_LOAD_IA32_PERF_GLOBAL_CTRL
+ *	are exposed to it, keep them filtered out.
  */
 #define EVMCS1_UNSUPPORTED_PINCTRL (PIN_BASED_POSTED_INTR | \
 				    PIN_BASED_VMX_PREEMPTION_TIMER)
@@ -58,7 +56,6 @@ DECLARE_STATIC_KEY_FALSE(enable_evmcs);
 	 SECONDARY_EXEC_ENABLE_PML |					\
 	 SECONDARY_EXEC_ENABLE_VMFUNC |					\
 	 SECONDARY_EXEC_SHADOW_VMCS |					\
-	 SECONDARY_EXEC_TSC_SCALING |					\
 	 SECONDARY_EXEC_PAUSE_LOOP_EXITING)
 #define EVMCS1_UNSUPPORTED_VMEXIT_CTRL					\
 	(VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL |				\
-- 
2.35.3