Merge tag 'kvm-x86-pat_vmx_msrs-6.12' of https://github.com/kvm-x86/linux into HEAD

bonzini · bonzini · commit 43d97b2ebd30 · 2024-09-17T12:40:39.000-04:00
KVM VMX and x86 PAT MSR macro cleanup for 6.12:

 - Add common defines for the x86 architectural memory types, i.e. the types
   that are shared across PAT, MTRRs, VMCSes, and EPTPs.

 - Clean up the various VMX MSR macros to make the code self-documenting
   (inasmuch as possible), and to make it less painful to add new macros.
diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
@@ -36,6 +36,20 @@
 #define EFER_FFXSR		(1<<_EFER_FFXSR)
 #define EFER_AUTOIBRS		(1<<_EFER_AUTOIBRS)
 
+/*
+ * Architectural memory types that are common to MTRRs, PAT, VMX MSRs, etc.
+ * Most MSRs support/allow only a subset of memory types, but the values
+ * themselves are common across all relevant MSRs.
+ */
+#define X86_MEMTYPE_UC		0ull	/* Uncacheable, a.k.a. Strong Uncacheable */
+#define X86_MEMTYPE_WC		1ull	/* Write Combining */
+/* RESERVED			2 */
+/* RESERVED			3 */
+#define X86_MEMTYPE_WT		4ull	/* Write Through */
+#define X86_MEMTYPE_WP		5ull	/* Write Protected */
+#define X86_MEMTYPE_WB		6ull	/* Write Back */
+#define X86_MEMTYPE_UC_MINUS	7ull	/* Weak Uncacheabled (PAT only) */
+
 /* FRED MSRs */
 #define MSR_IA32_FRED_RSP0	0x1cc			/* Level 0 stack pointer */
 #define MSR_IA32_FRED_RSP1	0x1cd			/* Level 1 stack pointer */
@@ -363,6 +377,12 @@
 
 #define MSR_IA32_CR_PAT			0x00000277
 
+#define PAT_VALUE(p0, p1, p2, p3, p4, p5, p6, p7)			\
+	((X86_MEMTYPE_ ## p0)      | (X86_MEMTYPE_ ## p1 << 8)  |	\
+	(X86_MEMTYPE_ ## p2 << 16) | (X86_MEMTYPE_ ## p3 << 24) |	\
+	(X86_MEMTYPE_ ## p4 << 32) | (X86_MEMTYPE_ ## p5 << 40) |	\
+	(X86_MEMTYPE_ ## p6 << 48) | (X86_MEMTYPE_ ## p7 << 56))
+
 #define MSR_IA32_DEBUGCTLMSR		0x000001d9
 #define MSR_IA32_LASTBRANCHFROMIP	0x000001db
 #define MSR_IA32_LASTBRANCHTOIP		0x000001dc
@@ -1157,15 +1177,6 @@
 #define MSR_IA32_VMX_VMFUNC             0x00000491
 #define MSR_IA32_VMX_PROCBASED_CTLS3	0x00000492
 
-/* VMX_BASIC bits and bitmasks */
-#define VMX_BASIC_VMCS_SIZE_SHIFT	32
-#define VMX_BASIC_TRUE_CTLS		(1ULL << 55)
-#define VMX_BASIC_64		0x0001000000000000LLU
-#define VMX_BASIC_MEM_TYPE_SHIFT	50
-#define VMX_BASIC_MEM_TYPE_MASK	0x003c000000000000LLU
-#define VMX_BASIC_MEM_TYPE_WB	6LLU
-#define VMX_BASIC_INOUT		0x0040000000000000LLU
-
 /* Resctrl MSRs: */
 /* - Intel: */
 #define MSR_IA32_L3_QOS_CFG		0xc81
@@ -1183,11 +1194,6 @@
 #define MSR_IA32_SMBA_BW_BASE		0xc0000280
 #define MSR_IA32_EVT_CFG_BASE		0xc0000400
 
-/* MSR_IA32_VMX_MISC bits */
-#define MSR_IA32_VMX_MISC_INTEL_PT                 (1ULL << 14)
-#define MSR_IA32_VMX_MISC_VMWRITE_SHADOW_RO_FIELDS (1ULL << 29)
-#define MSR_IA32_VMX_MISC_PREEMPTION_TIMER_SCALE   0x1F
-
 /* AMD-V MSRs */
 #define MSR_VM_CR                       0xc0010114
 #define MSR_VM_IGNNE                    0xc0010115
diff --git a/arch/x86/include/asm/vmx.h b/arch/x86/include/asm/vmx.h
@@ -122,19 +122,17 @@
 
 #define VM_ENTRY_ALWAYSON_WITHOUT_TRUE_MSR	0x000011ff
 
-#define VMX_MISC_PREEMPTION_TIMER_RATE_MASK	0x0000001f
-#define VMX_MISC_SAVE_EFER_LMA			0x00000020
-#define VMX_MISC_ACTIVITY_HLT			0x00000040
-#define VMX_MISC_ACTIVITY_WAIT_SIPI		0x00000100
-#define VMX_MISC_ZERO_LEN_INS			0x40000000
-#define VMX_MISC_MSR_LIST_MULTIPLIER		512
-
 /* VMFUNC functions */
 #define VMFUNC_CONTROL_BIT(x)	BIT((VMX_FEATURE_##x & 0x1f) - 28)
 
 #define VMX_VMFUNC_EPTP_SWITCHING               VMFUNC_CONTROL_BIT(EPTP_SWITCHING)
 #define VMFUNC_EPTP_ENTRIES  512
 
+#define VMX_BASIC_32BIT_PHYS_ADDR_ONLY		BIT_ULL(48)
+#define VMX_BASIC_DUAL_MONITOR_TREATMENT	BIT_ULL(49)
+#define VMX_BASIC_INOUT				BIT_ULL(54)
+#define VMX_BASIC_TRUE_CTLS			BIT_ULL(55)
+
 static inline u32 vmx_basic_vmcs_revision_id(u64 vmx_basic)
 {
 	return vmx_basic & GENMASK_ULL(30, 0);
@@ -145,9 +143,30 @@ static inline u32 vmx_basic_vmcs_size(u64 vmx_basic)
 	return (vmx_basic & GENMASK_ULL(44, 32)) >> 32;
 }
 
+static inline u32 vmx_basic_vmcs_mem_type(u64 vmx_basic)
+{
+	return (vmx_basic & GENMASK_ULL(53, 50)) >> 50;
+}
+
+static inline u64 vmx_basic_encode_vmcs_info(u32 revision, u16 size, u8 memtype)
+{
+	return revision | ((u64)size << 32) | ((u64)memtype << 50);
+}
+
+#define VMX_MISC_SAVE_EFER_LMA			BIT_ULL(5)
+#define VMX_MISC_ACTIVITY_HLT			BIT_ULL(6)
+#define VMX_MISC_ACTIVITY_SHUTDOWN		BIT_ULL(7)
+#define VMX_MISC_ACTIVITY_WAIT_SIPI		BIT_ULL(8)
+#define VMX_MISC_INTEL_PT			BIT_ULL(14)
+#define VMX_MISC_RDMSR_IN_SMM			BIT_ULL(15)
+#define VMX_MISC_VMXOFF_BLOCK_SMI		BIT_ULL(28)
+#define VMX_MISC_VMWRITE_SHADOW_RO_FIELDS	BIT_ULL(29)
+#define VMX_MISC_ZERO_LEN_INS			BIT_ULL(30)
+#define VMX_MISC_MSR_LIST_MULTIPLIER		512
+
 static inline int vmx_misc_preemption_timer_rate(u64 vmx_misc)
 {
-	return vmx_misc & VMX_MISC_PREEMPTION_TIMER_RATE_MASK;
+	return vmx_misc & GENMASK_ULL(4, 0);
 }
 
 static inline int vmx_misc_cr3_count(u64 vmx_misc)
@@ -508,9 +527,10 @@ enum vmcs_field {
 #define VMX_EPTP_PWL_4				0x18ull
 #define VMX_EPTP_PWL_5				0x20ull
 #define VMX_EPTP_AD_ENABLE_BIT			(1ull << 6)
+/* The EPTP memtype is encoded in bits 2:0, i.e. doesn't need to be shifted. */
 #define VMX_EPTP_MT_MASK			0x7ull
-#define VMX_EPTP_MT_WB				0x6ull
-#define VMX_EPTP_MT_UC				0x0ull
+#define VMX_EPTP_MT_WB				X86_MEMTYPE_WB
+#define VMX_EPTP_MT_UC				X86_MEMTYPE_UC
 #define VMX_EPT_READABLE_MASK			0x1ull
 #define VMX_EPT_WRITABLE_MASK			0x2ull
 #define VMX_EPT_EXECUTABLE_MASK			0x4ull
diff --git a/arch/x86/kernel/cpu/mtrr/mtrr.c b/arch/x86/kernel/cpu/mtrr/mtrr.c
@@ -55,6 +55,12 @@
 
 #include "mtrr.h"
 
+static_assert(X86_MEMTYPE_UC == MTRR_TYPE_UNCACHABLE);
+static_assert(X86_MEMTYPE_WC == MTRR_TYPE_WRCOMB);
+static_assert(X86_MEMTYPE_WT == MTRR_TYPE_WRTHROUGH);
+static_assert(X86_MEMTYPE_WP == MTRR_TYPE_WRPROT);
+static_assert(X86_MEMTYPE_WB == MTRR_TYPE_WRBACK);
+
 /* arch_phys_wc_add returns an MTRR register index plus this offset. */
 #define MTRR_TO_PHYS_WC_OFFSET 1000
 
diff --git a/arch/x86/kvm/vmx/capabilities.h b/arch/x86/kvm/vmx/capabilities.h
@@ -54,9 +54,7 @@ struct nested_vmx_msrs {
 };
 
 struct vmcs_config {
-	int size;
-	u32 basic_cap;
-	u32 revision_id;
+	u64 basic;
 	u32 pin_based_exec_ctrl;
 	u32 cpu_based_exec_ctrl;
 	u32 cpu_based_2nd_exec_ctrl;
@@ -76,7 +74,7 @@ extern struct vmx_capability vmx_capability __ro_after_init;
 
 static inline bool cpu_has_vmx_basic_inout(void)
 {
-	return	(((u64)vmcs_config.basic_cap << 32) & VMX_BASIC_INOUT);
+	return	vmcs_config.basic & VMX_BASIC_INOUT;
 }
 
 static inline bool cpu_has_virtual_nmis(void)
@@ -225,7 +223,7 @@ static inline bool cpu_has_vmx_vmfunc(void)
 static inline bool cpu_has_vmx_shadow_vmcs(void)
 {
 	/* check if the cpu supports writing r/o exit information fields */
-	if (!(vmcs_config.misc & MSR_IA32_VMX_MISC_VMWRITE_SHADOW_RO_FIELDS))
+	if (!(vmcs_config.misc & VMX_MISC_VMWRITE_SHADOW_RO_FIELDS))
 		return false;
 
 	return vmcs_config.cpu_based_2nd_exec_ctrl &
@@ -367,7 +365,7 @@ static inline bool cpu_has_vmx_invvpid_global(void)
 
 static inline bool cpu_has_vmx_intel_pt(void)
 {
-	return (vmcs_config.misc & MSR_IA32_VMX_MISC_INTEL_PT) &&
+	return (vmcs_config.misc & VMX_MISC_INTEL_PT) &&
 		(vmcs_config.cpu_based_2nd_exec_ctrl & SECONDARY_EXEC_PT_USE_GPA) &&
 		(vmcs_config.vmentry_ctrl & VM_ENTRY_LOAD_IA32_RTIT_CTL);
 }
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
@@ -1251,21 +1251,32 @@ static bool is_bitwise_subset(u64 superset, u64 subset, u64 mask)
 
 static int vmx_restore_vmx_basic(struct vcpu_vmx *vmx, u64 data)
 {
-	const u64 feature_and_reserved =
-		/* feature (except bit 48; see below) */
-		BIT_ULL(49) | BIT_ULL(54) | BIT_ULL(55) |
-		/* reserved */
-		BIT_ULL(31) | GENMASK_ULL(47, 45) | GENMASK_ULL(63, 56);
+	const u64 feature_bits = VMX_BASIC_DUAL_MONITOR_TREATMENT |
+				 VMX_BASIC_INOUT |
+				 VMX_BASIC_TRUE_CTLS;
+
+	const u64 reserved_bits = GENMASK_ULL(63, 56) |
+				  GENMASK_ULL(47, 45) |
+				  BIT_ULL(31);
+
 	u64 vmx_basic = vmcs_config.nested.basic;
 
-	if (!is_bitwise_subset(vmx_basic, data, feature_and_reserved))
+	BUILD_BUG_ON(feature_bits & reserved_bits);
+
+	/*
+	 * Except for 32BIT_PHYS_ADDR_ONLY, which is an anti-feature bit (has
+	 * inverted polarity), the incoming value must not set feature bits or
+	 * reserved bits that aren't allowed/supported by KVM.  Fields, i.e.
+	 * multi-bit values, are explicitly checked below.
+	 */
+	if (!is_bitwise_subset(vmx_basic, data, feature_bits | reserved_bits))
 		return -EINVAL;
 
 	/*
 	 * KVM does not emulate a version of VMX that constrains physical
 	 * addresses of VMX structures (e.g. VMCS) to 32-bits.
 	 */
-	if (data & BIT_ULL(48))
+	if (data & VMX_BASIC_32BIT_PHYS_ADDR_ONLY)
 		return -EINVAL;
 
 	if (vmx_basic_vmcs_revision_id(vmx_basic) !=
@@ -1334,16 +1345,29 @@ vmx_restore_control_msr(struct vcpu_vmx *vmx, u32 msr_index, u64 data)
 
 static int vmx_restore_vmx_misc(struct vcpu_vmx *vmx, u64 data)
 {
-	const u64 feature_and_reserved_bits =
-		/* feature */
-		BIT_ULL(5) | GENMASK_ULL(8, 6) | BIT_ULL(14) | BIT_ULL(15) |
-		BIT_ULL(28) | BIT_ULL(29) | BIT_ULL(30) |
-		/* reserved */
-		GENMASK_ULL(13, 9) | BIT_ULL(31);
+	const u64 feature_bits = VMX_MISC_SAVE_EFER_LMA |
+				 VMX_MISC_ACTIVITY_HLT |
+				 VMX_MISC_ACTIVITY_SHUTDOWN |
+				 VMX_MISC_ACTIVITY_WAIT_SIPI |
+				 VMX_MISC_INTEL_PT |
+				 VMX_MISC_RDMSR_IN_SMM |
+				 VMX_MISC_VMWRITE_SHADOW_RO_FIELDS |
+				 VMX_MISC_VMXOFF_BLOCK_SMI |
+				 VMX_MISC_ZERO_LEN_INS;
+
+	const u64 reserved_bits = BIT_ULL(31) | GENMASK_ULL(13, 9);
+
 	u64 vmx_misc = vmx_control_msr(vmcs_config.nested.misc_low,
 				       vmcs_config.nested.misc_high);
 
-	if (!is_bitwise_subset(vmx_misc, data, feature_and_reserved_bits))
+	BUILD_BUG_ON(feature_bits & reserved_bits);
+
+	/*
+	 * The incoming value must not set feature bits or reserved bits that
+	 * aren't allowed/supported by KVM.  Fields, i.e. multi-bit values, are
+	 * explicitly checked below.
+	 */
+	if (!is_bitwise_subset(vmx_misc, data, feature_bits | reserved_bits))
 		return -EINVAL;
 
 	if ((vmx->nested.msrs.pinbased_ctls_high &
@@ -7051,7 +7075,7 @@ static void nested_vmx_setup_misc_data(struct vmcs_config *vmcs_conf,
 {
 	msrs->misc_low = (u32)vmcs_conf->misc & VMX_MISC_SAVE_EFER_LMA;
 	msrs->misc_low |=
-		MSR_IA32_VMX_MISC_VMWRITE_SHADOW_RO_FIELDS |
+		VMX_MISC_VMWRITE_SHADOW_RO_FIELDS |
 		VMX_MISC_EMULATED_PREEMPTION_TIMER_RATE |
 		VMX_MISC_ACTIVITY_HLT |
 		VMX_MISC_ACTIVITY_WAIT_SIPI;
@@ -7066,12 +7090,10 @@ static void nested_vmx_setup_basic(struct nested_vmx_msrs *msrs)
 	 * guest, and the VMCS structure we give it - not about the
 	 * VMX support of the underlying hardware.
 	 */
-	msrs->basic =
-		VMCS12_REVISION |
-		VMX_BASIC_TRUE_CTLS |
-		((u64)VMCS12_SIZE << VMX_BASIC_VMCS_SIZE_SHIFT) |
-		(VMX_BASIC_MEM_TYPE_WB << VMX_BASIC_MEM_TYPE_SHIFT);
+	msrs->basic = vmx_basic_encode_vmcs_info(VMCS12_REVISION, VMCS12_SIZE,
+						 X86_MEMTYPE_WB);
 
+	msrs->basic |= VMX_BASIC_TRUE_CTLS;
 	if (cpu_has_vmx_basic_inout())
 		msrs->basic |= VMX_BASIC_INOUT;
 }
diff --git a/arch/x86/kvm/vmx/nested.h b/arch/x86/kvm/vmx/nested.h
@@ -109,7 +109,7 @@ static inline unsigned nested_cpu_vmx_misc_cr3_count(struct kvm_vcpu *vcpu)
 static inline bool nested_cpu_has_vmwrite_any_field(struct kvm_vcpu *vcpu)
 {
 	return to_vmx(vcpu)->nested.msrs.misc_low &
-		MSR_IA32_VMX_MISC_VMWRITE_SHADOW_RO_FIELDS;
+		VMX_MISC_VMWRITE_SHADOW_RO_FIELDS;
 }
 
 static inline bool nested_cpu_has_zero_length_injection(struct kvm_vcpu *vcpu)
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
@@ -2605,13 +2605,13 @@ static u64 adjust_vmx_controls64(u64 ctl_opt, u32 msr)
 static int setup_vmcs_config(struct vmcs_config *vmcs_conf,
 			     struct vmx_capability *vmx_cap)
 {
-	u32 vmx_msr_low, vmx_msr_high;
 	u32 _pin_based_exec_control = 0;
 	u32 _cpu_based_exec_control = 0;
 	u32 _cpu_based_2nd_exec_control = 0;
 	u64 _cpu_based_3rd_exec_control = 0;
 	u32 _vmexit_control = 0;
 	u32 _vmentry_control = 0;
+	u64 basic_msr;
 	u64 misc_msr;
 	int i;
 
@@ -2734,29 +2734,29 @@ static int setup_vmcs_config(struct vmcs_config *vmcs_conf,
 		_vmexit_control &= ~x_ctrl;
 	}
 
-	rdmsr(MSR_IA32_VMX_BASIC, vmx_msr_low, vmx_msr_high);
+	rdmsrl(MSR_IA32_VMX_BASIC, basic_msr);
 
 	/* IA-32 SDM Vol 3B: VMCS size is never greater than 4kB. */
-	if ((vmx_msr_high & 0x1fff) > PAGE_SIZE)
+	if (vmx_basic_vmcs_size(basic_msr) > PAGE_SIZE)
 		return -EIO;
 
 #ifdef CONFIG_X86_64
-	/* IA-32 SDM Vol 3B: 64-bit CPUs always have VMX_BASIC_MSR[48]==0. */
-	if (vmx_msr_high & (1u<<16))
+	/*
+	 * KVM expects to be able to shove all legal physical addresses into
+	 * VMCS fields for 64-bit kernels, and per the SDM, "This bit is always
+	 * 0 for processors that support Intel 64 architecture".
+	 */
+	if (basic_msr & VMX_BASIC_32BIT_PHYS_ADDR_ONLY)
 		return -EIO;
 #endif
 
 	/* Require Write-Back (WB) memory type for VMCS accesses. */
-	if (((vmx_msr_high >> 18) & 15) != 6)
+	if (vmx_basic_vmcs_mem_type(basic_msr) != X86_MEMTYPE_WB)
 		return -EIO;
 
 	rdmsrl(MSR_IA32_VMX_MISC, misc_msr);
 
-	vmcs_conf->size = vmx_msr_high & 0x1fff;
-	vmcs_conf->basic_cap = vmx_msr_high & ~0x1fff;
-
-	vmcs_conf->revision_id = vmx_msr_low;
-
+	vmcs_conf->basic = basic_msr;
 	vmcs_conf->pin_based_exec_ctrl = _pin_based_exec_control;
 	vmcs_conf->cpu_based_exec_ctrl = _cpu_based_exec_control;
 	vmcs_conf->cpu_based_2nd_exec_ctrl = _cpu_based_2nd_exec_control;
@@ -2903,13 +2903,13 @@ struct vmcs *alloc_vmcs_cpu(bool shadow, int cpu, gfp_t flags)
 	if (!pages)
 		return NULL;
 	vmcs = page_address(pages);
-	memset(vmcs, 0, vmcs_config.size);
+	memset(vmcs, 0, vmx_basic_vmcs_size(vmcs_config.basic));
 
 	/* KVM supports Enlightened VMCS v1 only */
 	if (kvm_is_using_evmcs())
 		vmcs->hdr.revision_id = KVM_EVMCS_VERSION;
 	else
-		vmcs->hdr.revision_id = vmcs_config.revision_id;
+		vmcs->hdr.revision_id = vmx_basic_vmcs_revision_id(vmcs_config.basic);
 
 	if (shadow)
 		vmcs->hdr.shadow_vmcs = 1;
@@ -3002,7 +3002,7 @@ static __init int alloc_kvm_area(void)
 		 * physical CPU.
 		 */
 		if (kvm_is_using_evmcs())
-			vmcs->hdr.revision_id = vmcs_config.revision_id;
+			vmcs->hdr.revision_id = vmx_basic_vmcs_revision_id(vmcs_config.basic);
 
 		per_cpu(vmxarea, cpu) = vmcs;
 	}
@@ -8519,7 +8519,7 @@ __init int vmx_hardware_setup(void)
 		u64 use_timer_freq = 5000ULL * 1000 * 1000;
 
 		cpu_preemption_timer_multi =
-			vmcs_config.misc & VMX_MISC_PREEMPTION_TIMER_RATE_MASK;
+			vmx_misc_preemption_timer_rate(vmcs_config.misc);
 
 		if (tsc_khz)
 			use_timer_freq = (u64)tsc_khz * 1000;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h
diff --git a/arch/x86/mm/pat/memtype.c b/arch/x86/mm/pat/memtype.c

Original file line number	Diff line number	Diff line change
`@@ -109,7 +109,7 @@ static inline unsigned nested_cpu_vmx_misc_cr3_count(struct kvm_vcpu *vcpu)`
`109`	`109`	`static inline bool nested_cpu_has_vmwrite_any_field(struct kvm_vcpu *vcpu)`
`110`	`110`	`{`
`111`	`111`	`return to_vmx(vcpu)->nested.msrs.misc_low &`
`112`		`- MSR_IA32_VMX_MISC_VMWRITE_SHADOW_RO_FIELDS;`
	`112`	`+ VMX_MISC_VMWRITE_SHADOW_RO_FIELDS;`
`113`	`113`	`}`
`114`	`114`
`115`	`115`	`static inline bool nested_cpu_has_zero_length_injection(struct kvm_vcpu *vcpu)`