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KVM: nVMX: Clean up and fix pin-based execution controls

PATCH Applied Jan Kiszka 3 participants 9 messages Mar 13, 2013 – Mar 14, 2013

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Jan Kiszka

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#0 lore raw

PATCH 1/2 KVM: nVMX: Clean up and fix pin-based execution controls

Only interrupt and NMI exiting are mandatory for KVM to work, thus can be exposed to the guest unconditionally, virtual NMI exiting is optional. So we must not advertise it unless the host supports it.

Introduce the symbolic constant PIN_BASED_ALWAYSON_WITHOUT_TRUE_MSR at this chance.

---
 arch/x86/include/asm/vmx.h |    2 ++
 arch/x86/kvm/vmx.c         |   10 ++++++----
 2 files changed, 8 insertions(+), 4 deletions(-)
arch/x86/include/asm/vmx.h +2 -0
index e1cc048c..056bda5 100644
@@ -71,6 +71,8 @@
 #define PIN_BASED_NMI_EXITING                   0x00000008
 #define PIN_BASED_VIRTUAL_NMIS                  0x00000020
 
+#define PIN_BASED_ALWAYSON_WITHOUT_TRUE_MSR	0x00000016
+
 #define VM_EXIT_SAVE_DEBUG_CONTROLS             0x00000002
 #define VM_EXIT_HOST_ADDR_SPACE_SIZE            0x00000200
 #define VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL      0x00001000
arch/x86/kvm/vmx.c +6 -4
index f310bcf..0f0cc6a 100644
@@ -2041,14 +2041,16 @@ static __init void nested_vmx_setup_ctls_msrs(void)
 	 */
 
 	/* pin-based controls */
+	rdmsr(MSR_IA32_VMX_PINBASED_CTLS,
+	      nested_vmx_pinbased_ctls_low, nested_vmx_pinbased_ctls_high);
 	/*
 	 * According to the Intel spec, if bit 55 of VMX_BASIC is off (as it is
 	 * in our case), bits 1, 2 and 4 (i.e., 0x16) must be 1 in this MSR.
 	 */
-	nested_vmx_pinbased_ctls_low = 0x16 ;
-	nested_vmx_pinbased_ctls_high = 0x16 |
-		PIN_BASED_EXT_INTR_MASK | PIN_BASED_NMI_EXITING |
-		PIN_BASED_VIRTUAL_NMIS;
+	nested_vmx_pinbased_ctls_low |= PIN_BASED_ALWAYSON_WITHOUT_TRUE_MSR;
+	nested_vmx_pinbased_ctls_high &= PIN_BASED_EXT_INTR_MASK |
+		PIN_BASED_NMI_EXITING | PIN_BASED_VIRTUAL_NMIS;
+	nested_vmx_pinbased_ctls_high |= PIN_BASED_ALWAYSON_WITHOUT_TRUE_MSR;
 
 	/*
 	 * Exit controls
Signature · 1 line
1.7.3.4
author
#1 lore raw

PATCH 1/1 KVM: nVMX: Add preemption timer support

Provided the host has this feature, it's straightforward to offer it to the guest as well. We just need to load to timer value on L2 entry if the feature was enabled by L1 and watch out for the corresponding exit reason.

---
 arch/x86/include/asm/vmx.h      |    3 +++
 arch/x86/include/uapi/asm/vmx.h |    5 +++--
 arch/x86/kvm/vmx.c              |   17 ++++++++++++++---
 3 files changed, 20 insertions(+), 5 deletions(-)
arch/x86/include/asm/vmx.h +3 -0
index 056bda5..fc1c313 100644
@@ -70,6 +70,7 @@
 #define PIN_BASED_EXT_INTR_MASK                 0x00000001
 #define PIN_BASED_NMI_EXITING                   0x00000008
 #define PIN_BASED_VIRTUAL_NMIS                  0x00000020
+#define PIN_BASED_VMX_PREEMPTION_TIMER          0x00000040
 
 #define PIN_BASED_ALWAYSON_WITHOUT_TRUE_MSR	0x00000016
 
@@ -95,6 +96,7 @@
 
 #define VM_ENTRY_ALWAYSON_WITHOUT_TRUE_MSR	0x000011ff
 
+#define VMX_MISC_PREEMPTION_TIMER_RATE_MASK	0x0000001f
 #define VMX_MISC_SAVE_EFER_LMA			0x00000020
 
 /* VMCS Encodings */
@@ -217,6 +219,7 @@ enum vmcs_field {
 	GUEST_INTERRUPTIBILITY_INFO     = 0x00004824,
 	GUEST_ACTIVITY_STATE            = 0X00004826,
 	GUEST_SYSENTER_CS               = 0x0000482A,
+	VMX_PREEMPTION_TIMER_VALUE      = 0x0000482E,
 	HOST_IA32_SYSENTER_CS           = 0x00004c00,
 	CR0_GUEST_HOST_MASK             = 0x00006000,
 	CR4_GUEST_HOST_MASK             = 0x00006002,
arch/x86/include/uapi/asm/vmx.h +3 -2
index 2871fcc..d651082 100644
@@ -65,6 +65,7 @@
 #define EXIT_REASON_EOI_INDUCED         45
 #define EXIT_REASON_EPT_VIOLATION       48
 #define EXIT_REASON_EPT_MISCONFIG       49
+#define EXIT_REASON_PREEMPTION_TIMER    52
 #define EXIT_REASON_WBINVD              54
 #define EXIT_REASON_XSETBV              55
 #define EXIT_REASON_APIC_WRITE          56
@@ -110,7 +111,7 @@
 	{ EXIT_REASON_EOI_INDUCED,           "EOI_INDUCED" }, \
 	{ EXIT_REASON_INVALID_STATE,         "INVALID_STATE" }, \
 	{ EXIT_REASON_INVD,                  "INVD" }, \
-	{ EXIT_REASON_INVPCID,               "INVPCID" }
-
+	{ EXIT_REASON_INVPCID,               "INVPCID" }, \
+	{ EXIT_REASON_PREEMPTION_TIMER,      "PREEMPTION_TIMER" }
 
 #endif /* _UAPIVMX_H */
arch/x86/kvm/vmx.c +14 -3
index 0f0cc6a..5b8eeb6 100644
@@ -298,7 +298,8 @@ struct __packed vmcs12 {
 	u32 guest_activity_state;
 	u32 guest_sysenter_cs;
 	u32 host_ia32_sysenter_cs;
-	u32 padding32[8]; /* room for future expansion */
+	u32 vmx_preemption_timer_value;
+	u32 padding32[7]; /* room for future expansion */
 	u16 virtual_processor_id;
 	u16 guest_es_selector;
 	u16 guest_cs_selector;
@@ -537,6 +538,7 @@ static const unsigned short vmcs_field_to_offset_table[] = {
 	FIELD(GUEST_ACTIVITY_STATE, guest_activity_state),
 	FIELD(GUEST_SYSENTER_CS, guest_sysenter_cs),
 	FIELD(HOST_IA32_SYSENTER_CS, host_ia32_sysenter_cs),
+	FIELD(VMX_PREEMPTION_TIMER_VALUE, vmx_preemption_timer_value),
 	FIELD(CR0_GUEST_HOST_MASK, cr0_guest_host_mask),
 	FIELD(CR4_GUEST_HOST_MASK, cr4_guest_host_mask),
 	FIELD(CR0_READ_SHADOW, cr0_read_shadow),
@@ -2049,7 +2051,8 @@ static __init void nested_vmx_setup_ctls_msrs(void)
 	 */
 	nested_vmx_pinbased_ctls_low |= PIN_BASED_ALWAYSON_WITHOUT_TRUE_MSR;
 	nested_vmx_pinbased_ctls_high &= PIN_BASED_EXT_INTR_MASK |
-		PIN_BASED_NMI_EXITING | PIN_BASED_VIRTUAL_NMIS;
+		PIN_BASED_NMI_EXITING | PIN_BASED_VIRTUAL_NMIS |
+		PIN_BASED_VMX_PREEMPTION_TIMER;
 	nested_vmx_pinbased_ctls_high |= PIN_BASED_ALWAYSON_WITHOUT_TRUE_MSR;
 
 	/*
@@ -2110,7 +2113,8 @@ static __init void nested_vmx_setup_ctls_msrs(void)
 
 	/* miscellaneous data */
 	rdmsr(MSR_IA32_VMX_MISC, nested_vmx_misc_low, nested_vmx_misc_high);
-	nested_vmx_misc_low &= VMX_MISC_SAVE_EFER_LMA;
+	nested_vmx_misc_low &= VMX_MISC_PREEMPTION_TIMER_RATE_MASK |
+		VMX_MISC_SAVE_EFER_LMA;
 	nested_vmx_misc_high = 0;
 }
 
@@ -6191,6 +6195,9 @@ static bool nested_vmx_exit_handled(struct kvm_vcpu *vcpu)
 	case EXIT_REASON_EPT_VIOLATION:
 	case EXIT_REASON_EPT_MISCONFIG:
 		return 0;
+	case EXIT_REASON_PREEMPTION_TIMER:
+		return vmcs12->pin_based_vm_exec_control &
+			PIN_BASED_VMX_PREEMPTION_TIMER;
 	case EXIT_REASON_WBINVD:
 		return nested_cpu_has2(vmcs12, SECONDARY_EXEC_WBINVD_EXITING);
 	case EXIT_REASON_XSETBV:
@@ -6984,6 +6991,10 @@ static void prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12)
 		(vmcs_config.pin_based_exec_ctrl |
 		 vmcs12->pin_based_vm_exec_control));
 
+	if (vmcs12->pin_based_vm_exec_control & PIN_BASED_VMX_PREEMPTION_TIMER)
+		vmcs_write32(VMX_PREEMPTION_TIMER_VALUE,
+			     vmcs12->vmx_preemption_timer_value);
+
 	/*
 	 * Whether page-faults are trapped is determined by a combination of
 	 * 3 settings: PFEC_MASK, PFEC_MATCH and EXCEPTION_BITMAP.PF.
Signature · 1 line
1.7.3.4
maintainer Reviewed-by on v1 1/1
#2 lore raw

Re: [PATCH] KVM: nVMX: Add preemption timer support

Il 13/03/2013 11:31, Jan Kiszka ha scritto:

Quoted 116 lines

Provided the host has this feature, it's straightforward to offer it to the guest as well. We just need to load to timer value on L2 entry if the feature was enabled by L1 and watch out for the corresponding exit reason.

---
 arch/x86/include/asm/vmx.h      |    3 +++
 arch/x86/include/uapi/asm/vmx.h |    5 +++--
 arch/x86/kvm/vmx.c              |   17 ++++++++++++++---
 3 files changed, 20 insertions(+), 5 deletions(-)
arch/x86/include/asm/vmx.h +3 -0
index 056bda5..fc1c313 100644
@@ -70,6 +70,7 @@
 #define PIN_BASED_EXT_INTR_MASK                 0x00000001
 #define PIN_BASED_NMI_EXITING                   0x00000008
 #define PIN_BASED_VIRTUAL_NMIS                  0x00000020
+#define PIN_BASED_VMX_PREEMPTION_TIMER          0x00000040
 
 #define PIN_BASED_ALWAYSON_WITHOUT_TRUE_MSR	0x00000016
 
@@ -95,6 +96,7 @@
 
 #define VM_ENTRY_ALWAYSON_WITHOUT_TRUE_MSR	0x000011ff
 
+#define VMX_MISC_PREEMPTION_TIMER_RATE_MASK	0x0000001f
 #define VMX_MISC_SAVE_EFER_LMA			0x00000020
 
 /* VMCS Encodings */
@@ -217,6 +219,7 @@ enum vmcs_field {
 	GUEST_INTERRUPTIBILITY_INFO     = 0x00004824,
 	GUEST_ACTIVITY_STATE            = 0X00004826,
 	GUEST_SYSENTER_CS               = 0x0000482A,
+	VMX_PREEMPTION_TIMER_VALUE      = 0x0000482E,
 	HOST_IA32_SYSENTER_CS           = 0x00004c00,
 	CR0_GUEST_HOST_MASK             = 0x00006000,
 	CR4_GUEST_HOST_MASK             = 0x00006002,
arch/x86/include/uapi/asm/vmx.h +3 -2
index 2871fcc..d651082 100644
@@ -65,6 +65,7 @@
 #define EXIT_REASON_EOI_INDUCED         45
 #define EXIT_REASON_EPT_VIOLATION       48
 #define EXIT_REASON_EPT_MISCONFIG       49
+#define EXIT_REASON_PREEMPTION_TIMER    52
 #define EXIT_REASON_WBINVD              54
 #define EXIT_REASON_XSETBV              55
 #define EXIT_REASON_APIC_WRITE          56
@@ -110,7 +111,7 @@
 	{ EXIT_REASON_EOI_INDUCED,           "EOI_INDUCED" }, \
 	{ EXIT_REASON_INVALID_STATE,         "INVALID_STATE" }, \
 	{ EXIT_REASON_INVD,                  "INVD" }, \
-	{ EXIT_REASON_INVPCID,               "INVPCID" }
-
+	{ EXIT_REASON_INVPCID,               "INVPCID" }, \
+	{ EXIT_REASON_PREEMPTION_TIMER,      "PREEMPTION_TIMER" }
 
 #endif /* _UAPIVMX_H */
arch/x86/kvm/vmx.c +10 -3
index 0f0cc6a..5b8eeb6 100644
@@ -298,7 +298,8 @@ struct __packed vmcs12 {
 	u32 guest_activity_state;
 	u32 guest_sysenter_cs;
 	u32 host_ia32_sysenter_cs;
-	u32 padding32[8]; /* room for future expansion */
+	u32 vmx_preemption_timer_value;
+	u32 padding32[7]; /* room for future expansion */
 	u16 virtual_processor_id;
 	u16 guest_es_selector;
 	u16 guest_cs_selector;
@@ -537,6 +538,7 @@ static const unsigned short vmcs_field_to_offset_table[] = {
 	FIELD(GUEST_ACTIVITY_STATE, guest_activity_state),
 	FIELD(GUEST_SYSENTER_CS, guest_sysenter_cs),
 	FIELD(HOST_IA32_SYSENTER_CS, host_ia32_sysenter_cs),
+	FIELD(VMX_PREEMPTION_TIMER_VALUE, vmx_preemption_timer_value),
 	FIELD(CR0_GUEST_HOST_MASK, cr0_guest_host_mask),
 	FIELD(CR4_GUEST_HOST_MASK, cr4_guest_host_mask),
 	FIELD(CR0_READ_SHADOW, cr0_read_shadow),
@@ -2049,7 +2051,8 @@ static __init void nested_vmx_setup_ctls_msrs(void)
 	 */
 	nested_vmx_pinbased_ctls_low |= PIN_BASED_ALWAYSON_WITHOUT_TRUE_MSR;
 	nested_vmx_pinbased_ctls_high &= PIN_BASED_EXT_INTR_MASK |
-		PIN_BASED_NMI_EXITING | PIN_BASED_VIRTUAL_NMIS;
+		PIN_BASED_NMI_EXITING | PIN_BASED_VIRTUAL_NMIS |
+		PIN_BASED_VMX_PREEMPTION_TIMER;
 	nested_vmx_pinbased_ctls_high |= PIN_BASED_ALWAYSON_WITHOUT_TRUE_MSR;
 
 	/*
@@ -2110,7 +2113,8 @@ static __init void nested_vmx_setup_ctls_msrs(void)
 
 	/* miscellaneous data */
 	rdmsr(MSR_IA32_VMX_MISC, nested_vmx_misc_low, nested_vmx_misc_high);
-	nested_vmx_misc_low &= VMX_MISC_SAVE_EFER_LMA;
+	nested_vmx_misc_low &= VMX_MISC_PREEMPTION_TIMER_RATE_MASK |
+		VMX_MISC_SAVE_EFER_LMA;
 	nested_vmx_misc_high = 0;
 }
 
@@ -6191,6 +6195,9 @@ static bool nested_vmx_exit_handled(struct kvm_vcpu *vcpu)
 	case EXIT_REASON_EPT_VIOLATION:
 	case EXIT_REASON_EPT_MISCONFIG:
 		return 0;
+	case EXIT_REASON_PREEMPTION_TIMER:
+		return vmcs12->pin_based_vm_exec_control &
+			PIN_BASED_VMX_PREEMPTION_TIMER;
 	case EXIT_REASON_WBINVD:
 		return nested_cpu_has2(vmcs12, SECONDARY_EXEC_WBINVD_EXITING);
 	case EXIT_REASON_XSETBV:

arch/x86/kvm/vmx.c static void prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12) · line 7000

Quoted 10 lines
arch/x86/kvm/vmx.c +4 -0
@@ -6984,6 +6991,10 @@ static void prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12)
 		(vmcs_config.pin_based_exec_ctrl |
 		 vmcs12->pin_based_vm_exec_control));
 
+	if (vmcs12->pin_based_vm_exec_control & PIN_BASED_VMX_PREEMPTION_TIMER)
+		vmcs_write32(VMX_PREEMPTION_TIMER_VALUE,
+			     vmcs12->vmx_preemption_timer_value);
+
 	/*
 	 * Whether page-faults are trapped is determined by a combination of
 	 * 3 settings: PFEC_MASK, PFEC_MATCH and EXCEPTION_BITMAP.PF.
#3 lore raw

Re: [PATCH] KVM: nVMX: Add preemption timer support

In reply to Jan Kiszka
Quoted 25 lines · Jan Kiszka

Provided the host has this feature, it's straightforward to offer it to the guest as well. We just need to load to timer value on L2 entry if the feature was enabled by L1 and watch out for the corresponding exit reason.

---
 arch/x86/include/asm/vmx.h      |    3 +++
 arch/x86/include/uapi/asm/vmx.h |    5 +++--
 arch/x86/kvm/vmx.c              |   17 ++++++++++++++---
 3 files changed, 20 insertions(+), 5 deletions(-)
arch/x86/include/asm/vmx.h +1 -0
index 056bda5..fc1c313 100644
@@ -70,6 +70,7 @@
 #define PIN_BASED_EXT_INTR_MASK                 0x00000001
 #define PIN_BASED_NMI_EXITING                   0x00000008
 #define PIN_BASED_VIRTUAL_NMIS                  0x00000020
+#define PIN_BASED_VMX_PREEMPTION_TIMER          0x00000040
 
 #define PIN_BASED_ALWAYSON_WITHOUT_TRUE_MSR	0x00000016
 

arch/x86/include/asm/vmx.h line 100

Quoted 5 lines
arch/x86/include/asm/vmx.h +1 -0
@@ -95,6 +96,7 @@
 
 #define VM_ENTRY_ALWAYSON_WITHOUT_TRUE_MSR	0x000011ff
 
+#define VMX_MISC_PREEMPTION_TIMER_RATE_MASK	0x0000001f
 #define VMX_MISC_SAVE_EFER_LMA			0x00000020

What is this patch against? I do not see VMX_MISC_SAVE_EFER_LMA in kvm.git queue.

Quoted 97 lines
arch/x86/include/asm/vmx.h +1 -0
 /* VMCS Encodings */
@@ -217,6 +219,7 @@ enum vmcs_field {
 	GUEST_INTERRUPTIBILITY_INFO     = 0x00004824,
 	GUEST_ACTIVITY_STATE            = 0X00004826,
 	GUEST_SYSENTER_CS               = 0x0000482A,
+	VMX_PREEMPTION_TIMER_VALUE      = 0x0000482E,
 	HOST_IA32_SYSENTER_CS           = 0x00004c00,
 	CR0_GUEST_HOST_MASK             = 0x00006000,
 	CR4_GUEST_HOST_MASK             = 0x00006002,
arch/x86/include/uapi/asm/vmx.h +3 -2
index 2871fcc..d651082 100644
@@ -65,6 +65,7 @@
 #define EXIT_REASON_EOI_INDUCED         45
 #define EXIT_REASON_EPT_VIOLATION       48
 #define EXIT_REASON_EPT_MISCONFIG       49
+#define EXIT_REASON_PREEMPTION_TIMER    52
 #define EXIT_REASON_WBINVD              54
 #define EXIT_REASON_XSETBV              55
 #define EXIT_REASON_APIC_WRITE          56
@@ -110,7 +111,7 @@
 	{ EXIT_REASON_EOI_INDUCED,           "EOI_INDUCED" }, \
 	{ EXIT_REASON_INVALID_STATE,         "INVALID_STATE" }, \
 	{ EXIT_REASON_INVD,                  "INVD" }, \
-	{ EXIT_REASON_INVPCID,               "INVPCID" }
-
+	{ EXIT_REASON_INVPCID,               "INVPCID" }, \
+	{ EXIT_REASON_PREEMPTION_TIMER,      "PREEMPTION_TIMER" }
 
 #endif /* _UAPIVMX_H */
arch/x86/kvm/vmx.c +14 -3
index 0f0cc6a..5b8eeb6 100644
@@ -298,7 +298,8 @@ struct __packed vmcs12 {
 	u32 guest_activity_state;
 	u32 guest_sysenter_cs;
 	u32 host_ia32_sysenter_cs;
-	u32 padding32[8]; /* room for future expansion */
+	u32 vmx_preemption_timer_value;
+	u32 padding32[7]; /* room for future expansion */
 	u16 virtual_processor_id;
 	u16 guest_es_selector;
 	u16 guest_cs_selector;
@@ -537,6 +538,7 @@ static const unsigned short vmcs_field_to_offset_table[] = {
 	FIELD(GUEST_ACTIVITY_STATE, guest_activity_state),
 	FIELD(GUEST_SYSENTER_CS, guest_sysenter_cs),
 	FIELD(HOST_IA32_SYSENTER_CS, host_ia32_sysenter_cs),
+	FIELD(VMX_PREEMPTION_TIMER_VALUE, vmx_preemption_timer_value),
 	FIELD(CR0_GUEST_HOST_MASK, cr0_guest_host_mask),
 	FIELD(CR4_GUEST_HOST_MASK, cr4_guest_host_mask),
 	FIELD(CR0_READ_SHADOW, cr0_read_shadow),
@@ -2049,7 +2051,8 @@ static __init void nested_vmx_setup_ctls_msrs(void)
 	 */
 	nested_vmx_pinbased_ctls_low |= PIN_BASED_ALWAYSON_WITHOUT_TRUE_MSR;
 	nested_vmx_pinbased_ctls_high &= PIN_BASED_EXT_INTR_MASK |
-		PIN_BASED_NMI_EXITING | PIN_BASED_VIRTUAL_NMIS;
+		PIN_BASED_NMI_EXITING | PIN_BASED_VIRTUAL_NMIS |
+		PIN_BASED_VMX_PREEMPTION_TIMER;
 	nested_vmx_pinbased_ctls_high |= PIN_BASED_ALWAYSON_WITHOUT_TRUE_MSR;
 
 	/*
@@ -2110,7 +2113,8 @@ static __init void nested_vmx_setup_ctls_msrs(void)
 
 	/* miscellaneous data */
 	rdmsr(MSR_IA32_VMX_MISC, nested_vmx_misc_low, nested_vmx_misc_high);
-	nested_vmx_misc_low &= VMX_MISC_SAVE_EFER_LMA;
+	nested_vmx_misc_low &= VMX_MISC_PREEMPTION_TIMER_RATE_MASK |
+		VMX_MISC_SAVE_EFER_LMA;
 	nested_vmx_misc_high = 0;
 }
 
@@ -6191,6 +6195,9 @@ static bool nested_vmx_exit_handled(struct kvm_vcpu *vcpu)
 	case EXIT_REASON_EPT_VIOLATION:
 	case EXIT_REASON_EPT_MISCONFIG:
 		return 0;
+	case EXIT_REASON_PREEMPTION_TIMER:
+		return vmcs12->pin_based_vm_exec_control &
+			PIN_BASED_VMX_PREEMPTION_TIMER;
 	case EXIT_REASON_WBINVD:
 		return nested_cpu_has2(vmcs12, SECONDARY_EXEC_WBINVD_EXITING);
 	case EXIT_REASON_XSETBV:
@@ -6984,6 +6991,10 @@ static void prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12)
 		(vmcs_config.pin_based_exec_ctrl |
 		 vmcs12->pin_based_vm_exec_control));
 
+	if (vmcs12->pin_based_vm_exec_control & PIN_BASED_VMX_PREEMPTION_TIMER)
+		vmcs_write32(VMX_PREEMPTION_TIMER_VALUE,
+			     vmcs12->vmx_preemption_timer_value);
+
 	/*
 	 * Whether page-faults are trapped is determined by a combination of
 	 * 3 settings: PFEC_MASK, PFEC_MATCH and EXCEPTION_BITMAP.PF.
Signature · 1 line
1.7.3.4

--
Gleb.

author
#4 lore raw

Re: [PATCH] KVM: nVMX: Add preemption timer support

Quoted 25 lines · Gleb Natapov
Quoted 24 lines · Jan Kiszka

Provided the host has this feature, it's straightforward to offer it to the guest as well. We just need to load to timer value on L2 entry if the feature was enabled by L1 and watch out for the corresponding exit reason.

---
 arch/x86/include/asm/vmx.h      |    3 +++
 arch/x86/include/uapi/asm/vmx.h |    5 +++--
 arch/x86/kvm/vmx.c              |   17 ++++++++++++++---
 3 files changed, 20 insertions(+), 5 deletions(-)
arch/x86/include/asm/vmx.h +1 -0
index 056bda5..fc1c313 100644
@@ -70,6 +70,7 @@
 #define PIN_BASED_EXT_INTR_MASK                 0x00000001
 #define PIN_BASED_NMI_EXITING                   0x00000008
 #define PIN_BASED_VIRTUAL_NMIS                  0x00000020
+#define PIN_BASED_VMX_PREEMPTION_TIMER          0x00000040
 
 #define PIN_BASED_ALWAYSON_WITHOUT_TRUE_MSR	0x00000016
 
Quoted 8 lines

arch/x86/include/asm/vmx.h line 100

Quoted 6 lines
arch/x86/include/asm/vmx.h +1 -0
@@ -95,6 +96,7 @@
 
 #define VM_ENTRY_ALWAYSON_WITHOUT_TRUE_MSR	0x000011ff
 
+#define VMX_MISC_PREEMPTION_TIMER_RATE_MASK	0x0000001f
 #define VMX_MISC_SAVE_EFER_LMA			0x00000020

What is this patch against? I do not see VMX_MISC_SAVE_EFER_LMA in kvm.git queue.

Against my queue after adding support for nested EFER.LMA saving, sorry. I thought I posted that patch already, but I didn't. Will reorder (and send those other bits as well at that chance).

Jan

Signature · 2 lines
Siemens AG, Corporate Technology, CT RTC ITP SDP-DE
Corporate Competence Center Embedded Linux
author
#5 lore raw

Re: [PATCH] KVM: nVMX: Add preemption timer support

Quoted 30 lines · Jan Kiszka
Quoted 29 lines · Gleb Natapov
Quoted 28 lines · Jan Kiszka

Provided the host has this feature, it's straightforward to offer it to the guest as well. We just need to load to timer value on L2 entry if the feature was enabled by L1 and watch out for the corresponding exit reason.

---
 arch/x86/include/asm/vmx.h      |    3 +++
 arch/x86/include/uapi/asm/vmx.h |    5 +++--
 arch/x86/kvm/vmx.c              |   17 ++++++++++++++---
 3 files changed, 20 insertions(+), 5 deletions(-)
arch/x86/include/asm/vmx.h +1 -0
index 056bda5..fc1c313 100644
@@ -70,6 +70,7 @@
 #define PIN_BASED_EXT_INTR_MASK                 0x00000001
 #define PIN_BASED_NMI_EXITING                   0x00000008
 #define PIN_BASED_VIRTUAL_NMIS                  0x00000020
+#define PIN_BASED_VMX_PREEMPTION_TIMER          0x00000040
 
 #define PIN_BASED_ALWAYSON_WITHOUT_TRUE_MSR	0x00000016
 
@@ -95,6 +96,7 @@
 
 #define VM_ENTRY_ALWAYSON_WITHOUT_TRUE_MSR	0x000011ff
 
Quoted 8 lines
Quoted 4 lines

arch/x86/include/asm/vmx.h line 100

Quoted 2 lines
arch/x86/include/asm/vmx.h +1 -0
+#define VMX_MISC_PREEMPTION_TIMER_RATE_MASK	0x0000001f
 #define VMX_MISC_SAVE_EFER_LMA			0x00000020

What is this patch against? I do not see VMX_MISC_SAVE_EFER_LMA in kvm.git queue.

Against my queue after adding support for nested EFER.LMA saving, sorry. I thought I posted that patch already, but I didn't. Will reorder (and send those other bits as well at that chance).

In fact, the other way around is simpler: posting the missing patch.

Jan

Signature · 2 lines
Siemens AG, Corporate Technology, CT RTC ITP SDP-DE
Corporate Competence Center Embedded Linux
Applied
#6 lore raw

Re: [PATCH] KVM: nVMX: Add preemption timer support

In reply to Jan Kiszka
Quoted 6 lines · Jan Kiszka

Provided the host has this feature, it's straightforward to offer it to the guest as well. We just need to load to timer value on L2 entry if the feature was enabled by L1 and watch out for the corresponding exit reason.

Applied, thanks

Quoted 121 lines
---
 arch/x86/include/asm/vmx.h      |    3 +++
 arch/x86/include/uapi/asm/vmx.h |    5 +++--
 arch/x86/kvm/vmx.c              |   17 ++++++++++++++---
 3 files changed, 20 insertions(+), 5 deletions(-)
arch/x86/include/asm/vmx.h +3 -0
index 056bda5..fc1c313 100644
@@ -70,6 +70,7 @@
 #define PIN_BASED_EXT_INTR_MASK                 0x00000001
 #define PIN_BASED_NMI_EXITING                   0x00000008
 #define PIN_BASED_VIRTUAL_NMIS                  0x00000020
+#define PIN_BASED_VMX_PREEMPTION_TIMER          0x00000040
 
 #define PIN_BASED_ALWAYSON_WITHOUT_TRUE_MSR	0x00000016
 
@@ -95,6 +96,7 @@
 
 #define VM_ENTRY_ALWAYSON_WITHOUT_TRUE_MSR	0x000011ff
 
+#define VMX_MISC_PREEMPTION_TIMER_RATE_MASK	0x0000001f
 #define VMX_MISC_SAVE_EFER_LMA			0x00000020
 
 /* VMCS Encodings */
@@ -217,6 +219,7 @@ enum vmcs_field {
 	GUEST_INTERRUPTIBILITY_INFO     = 0x00004824,
 	GUEST_ACTIVITY_STATE            = 0X00004826,
 	GUEST_SYSENTER_CS               = 0x0000482A,
+	VMX_PREEMPTION_TIMER_VALUE      = 0x0000482E,
 	HOST_IA32_SYSENTER_CS           = 0x00004c00,
 	CR0_GUEST_HOST_MASK             = 0x00006000,
 	CR4_GUEST_HOST_MASK             = 0x00006002,
arch/x86/include/uapi/asm/vmx.h +3 -2
index 2871fcc..d651082 100644
@@ -65,6 +65,7 @@
 #define EXIT_REASON_EOI_INDUCED         45
 #define EXIT_REASON_EPT_VIOLATION       48
 #define EXIT_REASON_EPT_MISCONFIG       49
+#define EXIT_REASON_PREEMPTION_TIMER    52
 #define EXIT_REASON_WBINVD              54
 #define EXIT_REASON_XSETBV              55
 #define EXIT_REASON_APIC_WRITE          56
@@ -110,7 +111,7 @@
 	{ EXIT_REASON_EOI_INDUCED,           "EOI_INDUCED" }, \
 	{ EXIT_REASON_INVALID_STATE,         "INVALID_STATE" }, \
 	{ EXIT_REASON_INVD,                  "INVD" }, \
-	{ EXIT_REASON_INVPCID,               "INVPCID" }
-
+	{ EXIT_REASON_INVPCID,               "INVPCID" }, \
+	{ EXIT_REASON_PREEMPTION_TIMER,      "PREEMPTION_TIMER" }
 
 #endif /* _UAPIVMX_H */
arch/x86/kvm/vmx.c +14 -3
index 0f0cc6a..5b8eeb6 100644
@@ -298,7 +298,8 @@ struct __packed vmcs12 {
 	u32 guest_activity_state;
 	u32 guest_sysenter_cs;
 	u32 host_ia32_sysenter_cs;
-	u32 padding32[8]; /* room for future expansion */
+	u32 vmx_preemption_timer_value;
+	u32 padding32[7]; /* room for future expansion */
 	u16 virtual_processor_id;
 	u16 guest_es_selector;
 	u16 guest_cs_selector;
@@ -537,6 +538,7 @@ static const unsigned short vmcs_field_to_offset_table[] = {
 	FIELD(GUEST_ACTIVITY_STATE, guest_activity_state),
 	FIELD(GUEST_SYSENTER_CS, guest_sysenter_cs),
 	FIELD(HOST_IA32_SYSENTER_CS, host_ia32_sysenter_cs),
+	FIELD(VMX_PREEMPTION_TIMER_VALUE, vmx_preemption_timer_value),
 	FIELD(CR0_GUEST_HOST_MASK, cr0_guest_host_mask),
 	FIELD(CR4_GUEST_HOST_MASK, cr4_guest_host_mask),
 	FIELD(CR0_READ_SHADOW, cr0_read_shadow),
@@ -2049,7 +2051,8 @@ static __init void nested_vmx_setup_ctls_msrs(void)
 	 */
 	nested_vmx_pinbased_ctls_low |= PIN_BASED_ALWAYSON_WITHOUT_TRUE_MSR;
 	nested_vmx_pinbased_ctls_high &= PIN_BASED_EXT_INTR_MASK |
-		PIN_BASED_NMI_EXITING | PIN_BASED_VIRTUAL_NMIS;
+		PIN_BASED_NMI_EXITING | PIN_BASED_VIRTUAL_NMIS |
+		PIN_BASED_VMX_PREEMPTION_TIMER;
 	nested_vmx_pinbased_ctls_high |= PIN_BASED_ALWAYSON_WITHOUT_TRUE_MSR;
 
 	/*
@@ -2110,7 +2113,8 @@ static __init void nested_vmx_setup_ctls_msrs(void)
 
 	/* miscellaneous data */
 	rdmsr(MSR_IA32_VMX_MISC, nested_vmx_misc_low, nested_vmx_misc_high);
-	nested_vmx_misc_low &= VMX_MISC_SAVE_EFER_LMA;
+	nested_vmx_misc_low &= VMX_MISC_PREEMPTION_TIMER_RATE_MASK |
+		VMX_MISC_SAVE_EFER_LMA;
 	nested_vmx_misc_high = 0;
 }
 
@@ -6191,6 +6195,9 @@ static bool nested_vmx_exit_handled(struct kvm_vcpu *vcpu)
 	case EXIT_REASON_EPT_VIOLATION:
 	case EXIT_REASON_EPT_MISCONFIG:
 		return 0;
+	case EXIT_REASON_PREEMPTION_TIMER:
+		return vmcs12->pin_based_vm_exec_control &
+			PIN_BASED_VMX_PREEMPTION_TIMER;
 	case EXIT_REASON_WBINVD:
 		return nested_cpu_has2(vmcs12, SECONDARY_EXEC_WBINVD_EXITING);
 	case EXIT_REASON_XSETBV:
@@ -6984,6 +6991,10 @@ static void prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12)
 		(vmcs_config.pin_based_exec_ctrl |
 		 vmcs12->pin_based_vm_exec_control));
 
+	if (vmcs12->pin_based_vm_exec_control & PIN_BASED_VMX_PREEMPTION_TIMER)
+		vmcs_write32(VMX_PREEMPTION_TIMER_VALUE,
+			     vmcs12->vmx_preemption_timer_value);
+
 	/*
 	 * Whether page-faults are trapped is determined by a combination of
 	 * 3 settings: PFEC_MASK, PFEC_MATCH and EXCEPTION_BITMAP.PF.
Signature · 1 line
1.7.3.4

--
Gleb.

maintainer Reviewed-by on v1 1/2
#7 lore raw
In reply to Jan Kiszka

Il 13/03/2013 11:30, Jan Kiszka ha scritto:

Quoted 42 lines

Only interrupt and NMI exiting are mandatory for KVM to work, thus can be exposed to the guest unconditionally, virtual NMI exiting is optional. So we must not advertise it unless the host supports it.

Introduce the symbolic constant PIN_BASED_ALWAYSON_WITHOUT_TRUE_MSR at this chance.

---
 arch/x86/include/asm/vmx.h |    2 ++
 arch/x86/kvm/vmx.c         |   10 ++++++----
 2 files changed, 8 insertions(+), 4 deletions(-)
arch/x86/include/asm/vmx.h +2 -0
index e1cc048c..056bda5 100644
@@ -71,6 +71,8 @@
 #define PIN_BASED_NMI_EXITING                   0x00000008
 #define PIN_BASED_VIRTUAL_NMIS                  0x00000020
 
+#define PIN_BASED_ALWAYSON_WITHOUT_TRUE_MSR	0x00000016
+
 #define VM_EXIT_SAVE_DEBUG_CONTROLS             0x00000002
 #define VM_EXIT_HOST_ADDR_SPACE_SIZE            0x00000200
 #define VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL      0x00001000
arch/x86/kvm/vmx.c +2 -1
index f310bcf..0f0cc6a 100644
@@ -2041,14 +2041,16 @@ static __init void nested_vmx_setup_ctls_msrs(void)
 	 */
 
 	/* pin-based controls */
+	rdmsr(MSR_IA32_VMX_PINBASED_CTLS,
+	      nested_vmx_pinbased_ctls_low, nested_vmx_pinbased_ctls_high);
 	/*
 	 * According to the Intel spec, if bit 55 of VMX_BASIC is off (as it is
 	 * in our case), bits 1, 2 and 4 (i.e., 0x16) must be 1 in this MSR.
 	 */
-	nested_vmx_pinbased_ctls_low = 0x16 ;

arch/x86/kvm/vmx.c static __init void nested_vmx_setup_ctls_msrs(void) · line 2056

Quoted 10 lines
arch/x86/kvm/vmx.c +4 -3
-	nested_vmx_pinbased_ctls_high = 0x16 |
-		PIN_BASED_EXT_INTR_MASK | PIN_BASED_NMI_EXITING |
-		PIN_BASED_VIRTUAL_NMIS;
+	nested_vmx_pinbased_ctls_low |= PIN_BASED_ALWAYSON_WITHOUT_TRUE_MSR;
+	nested_vmx_pinbased_ctls_high &= PIN_BASED_EXT_INTR_MASK |
+		PIN_BASED_NMI_EXITING | PIN_BASED_VIRTUAL_NMIS;
+	nested_vmx_pinbased_ctls_high |= PIN_BASED_ALWAYSON_WITHOUT_TRUE_MSR;
 
 	/*
 	 * Exit controls
Applied
#8 lore raw
In reply to Jan Kiszka
Quoted 8 lines · Jan Kiszka

Only interrupt and NMI exiting are mandatory for KVM to work, thus can be exposed to the guest unconditionally, virtual NMI exiting is optional. So we must not advertise it unless the host supports it.

Introduce the symbolic constant PIN_BASED_ALWAYSON_WITHOUT_TRUE_MSR at this chance.

Applied, thanks.

Quoted 45 lines
---
 arch/x86/include/asm/vmx.h |    2 ++
 arch/x86/kvm/vmx.c         |   10 ++++++----
 2 files changed, 8 insertions(+), 4 deletions(-)
arch/x86/include/asm/vmx.h +2 -0
index e1cc048c..056bda5 100644
@@ -71,6 +71,8 @@
 #define PIN_BASED_NMI_EXITING                   0x00000008
 #define PIN_BASED_VIRTUAL_NMIS                  0x00000020
 
+#define PIN_BASED_ALWAYSON_WITHOUT_TRUE_MSR	0x00000016
+
 #define VM_EXIT_SAVE_DEBUG_CONTROLS             0x00000002
 #define VM_EXIT_HOST_ADDR_SPACE_SIZE            0x00000200
 #define VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL      0x00001000
arch/x86/kvm/vmx.c +6 -4
index f310bcf..0f0cc6a 100644
@@ -2041,14 +2041,16 @@ static __init void nested_vmx_setup_ctls_msrs(void)
 	 */
 
 	/* pin-based controls */
+	rdmsr(MSR_IA32_VMX_PINBASED_CTLS,
+	      nested_vmx_pinbased_ctls_low, nested_vmx_pinbased_ctls_high);
 	/*
 	 * According to the Intel spec, if bit 55 of VMX_BASIC is off (as it is
 	 * in our case), bits 1, 2 and 4 (i.e., 0x16) must be 1 in this MSR.
 	 */
-	nested_vmx_pinbased_ctls_low = 0x16 ;
-	nested_vmx_pinbased_ctls_high = 0x16 |
-		PIN_BASED_EXT_INTR_MASK | PIN_BASED_NMI_EXITING |
-		PIN_BASED_VIRTUAL_NMIS;
+	nested_vmx_pinbased_ctls_low |= PIN_BASED_ALWAYSON_WITHOUT_TRUE_MSR;
+	nested_vmx_pinbased_ctls_high &= PIN_BASED_EXT_INTR_MASK |
+		PIN_BASED_NMI_EXITING | PIN_BASED_VIRTUAL_NMIS;
+	nested_vmx_pinbased_ctls_high |= PIN_BASED_ALWAYSON_WITHOUT_TRUE_MSR;
 
 	/*
 	 * Exit controls
Signature · 1 line
1.7.3.4

--
Gleb.