[v1,01/23] KVM: VMX: Cleanup VMX basic information defines and usages

Commit Message

Li, Xin3 Nov. 8, 2023, 6:29 p.m. UTC

Define VMX basic information fields with BIT_ULL()/GENMASK_ULL(), and
replace hardcoded VMX basic numbers with these field macros.

Per Sean's ask, save the full/raw value of MSR_IA32_VMX_BASIC in the
global vmcs_config as type u64 to get rid of the hi/lo crud, and then
use VMX_BASIC helpers to extract info as needed.

Tested-by: Shan Kang <[e-mail]>
Signed-off-by: Xin Li <[e-mail]>
---

Changes since v2:
* Simply save the full/raw value of MSR_IA32_VMX_BASIC in the global
  vmcs_config, and then use the helpers to extract info from it as
  needed (Sean Christopherson).
* Move all VMX_MISC related changes to the second patch (Kai Huang).
* Commonize memory type definitions used in the VMX files, as memory
  types are architectural.

Changes since v1:
* Don't add field shift macros unless it's really needed, extra layer
  of indirect makes it harder to read (Sean Christopherson).
* Add a static_assert() to ensure that VMX_BASIC_FEATURES_MASK doesn't
  overlap with VMX_BASIC_RESERVED_BITS (Sean Christopherson).
* read MSR_IA32_VMX_BASIC into an u64 rather than 2 u32 (Sean
  Christopherson).
* Add 2 new functions for extracting fields from VMX basic (Sean
  Christopherson).
* Drop the tools header update (Sean Christopherson).
* Move VMX basic field macros to arch/x86/include/asm/vmx.h.
---
 arch/x86/include/asm/msr-index.h |  9 ---------
 arch/x86/include/asm/vmx.h       | 15 +++++++++++++--
 arch/x86/kvm/vmx/capabilities.h  |  6 ++----
 arch/x86/kvm/vmx/nested.c        | 31 +++++++++++++++++++++----------
 arch/x86/kvm/vmx/vmx.c           | 24 ++++++++++--------------
 5 files changed, 46 insertions(+), 39 deletions(-)

Patch

diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
index d1d6b3c3e6bd..68c75c299300 100644
--- a/arch/x86/include/asm/msr-index.h
+++ b/arch/x86/include/asm/msr-index.h
@@ -1110,15 +1110,6 @@ 
 #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
diff --git a/arch/x86/include/asm/vmx.h b/arch/x86/include/asm/vmx.h
index 4dba17363008..273960225a3b 100644
--- a/arch/x86/include/asm/vmx.h
+++ b/arch/x86/include/asm/vmx.h
@@ -121,6 +121,14 @@ 
 
 #define VM_ENTRY_ALWAYSON_WITHOUT_TRUE_MSR	0x000011ff
 
+/* x86 memory types, explicitly used in VMX only */
+#define MEM_TYPE_WB				0x6ULL
+#define MEM_TYPE_UC				0x0ULL
+
+/* VMX_BASIC bits and bitmasks */
+#define VMX_BASIC_32BIT_PHYS_ADDR_ONLY		BIT_ULL(48)
+#define VMX_BASIC_INOUT				BIT_ULL(54)
+
 #define VMX_MISC_PREEMPTION_TIMER_RATE_MASK	0x0000001f
 #define VMX_MISC_SAVE_EFER_LMA			0x00000020
 #define VMX_MISC_ACTIVITY_HLT			0x00000040
@@ -144,6 +152,11 @@  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 int vmx_misc_preemption_timer_rate(u64 vmx_misc)
 {
 	return vmx_misc & VMX_MISC_PREEMPTION_TIMER_RATE_MASK;
@@ -506,8 +519,6 @@  enum vmcs_field {
 #define VMX_EPTP_PWL_5				0x20ull
 #define VMX_EPTP_AD_ENABLE_BIT			(1ull << 6)
 #define VMX_EPTP_MT_MASK			0x7ull
-#define VMX_EPTP_MT_WB				0x6ull
-#define VMX_EPTP_MT_UC				0x0ull
 #define VMX_EPT_READABLE_MASK			0x1ull
 #define VMX_EPT_WRITABLE_MASK			0x2ull
 #define VMX_EPT_EXECUTABLE_MASK			0x4ull
diff --git a/arch/x86/kvm/vmx/capabilities.h b/arch/x86/kvm/vmx/capabilities.h
index 41a4533f9989..86ce8bb96bed 100644
--- 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)
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index c5ec0ef51ff7..23704f8d9035 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -1201,23 +1201,34 @@  static bool is_bitwise_subset(u64 superset, u64 subset, u64 mask)
 	return (superset | subset) == superset;
 }
 
+#define VMX_BASIC_VMCS_SIZE_SHIFT		32
+#define VMX_BASIC_DUAL_MONITOR_TREATMENT	BIT_ULL(49)
+#define VMX_BASIC_MEM_TYPE_SHIFT		50
+#define VMX_BASIC_TRUE_CTLS			BIT_ULL(55)
+
+#define VMX_BASIC_FEATURES_MASK			\
+	(VMX_BASIC_DUAL_MONITOR_TREATMENT |	\
+	 VMX_BASIC_INOUT |			\
+	 VMX_BASIC_TRUE_CTLS)
+
+#define VMX_BASIC_RESERVED_BITS			\
+	(GENMASK_ULL(63, 56) | GENMASK_ULL(47, 45) | BIT_ULL(31))
+
 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);
 	u64 vmx_basic = vmcs_config.nested.basic;
 
-	if (!is_bitwise_subset(vmx_basic, data, feature_and_reserved))
+	static_assert(!(VMX_BASIC_FEATURES_MASK & VMX_BASIC_RESERVED_BITS));
+
+	if (!is_bitwise_subset(vmx_basic, data,
+			       VMX_BASIC_FEATURES_MASK | VMX_BASIC_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) !=
@@ -2690,11 +2701,11 @@  static bool nested_vmx_check_eptp(struct kvm_vcpu *vcpu, u64 new_eptp)
 
 	/* Check for memory type validity */
 	switch (new_eptp & VMX_EPTP_MT_MASK) {
-	case VMX_EPTP_MT_UC:
+	case MEM_TYPE_UC:
 		if (CC(!(vmx->nested.msrs.ept_caps & VMX_EPTP_UC_BIT)))
 			return false;
 		break;
-	case VMX_EPTP_MT_WB:
+	case MEM_TYPE_WB:
 		if (CC(!(vmx->nested.msrs.ept_caps & VMX_EPTP_WB_BIT)))
 			return false;
 		break;
@@ -6964,7 +6975,7 @@  static void nested_vmx_setup_basic(struct nested_vmx_msrs *msrs)
 		VMCS12_REVISION |
 		VMX_BASIC_TRUE_CTLS |
 		((u64)VMCS12_SIZE << VMX_BASIC_VMCS_SIZE_SHIFT) |
-		(VMX_BASIC_MEM_TYPE_WB << VMX_BASIC_MEM_TYPE_SHIFT);
+		(MEM_TYPE_WB << VMX_BASIC_MEM_TYPE_SHIFT);
 
 	if (cpu_has_vmx_basic_inout())
 		msrs->basic |= VMX_BASIC_INOUT;
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index ba5cd26137e0..6b3b2df11cea 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -2569,13 +2569,13 @@  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;
 
@@ -2694,29 +2694,25 @@  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))
+	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) != MEM_TYPE_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;
@@ -2866,13 +2862,13 @@  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;
@@ -2965,7 +2961,7 @@  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;
 	}
@@ -3367,7 +3363,7 @@  static int vmx_get_max_ept_level(void)
 
 u64 construct_eptp(struct kvm_vcpu *vcpu, hpa_t root_hpa, int root_level)
 {
-	u64 eptp = VMX_EPTP_MT_WB;
+	u64 eptp = MEM_TYPE_WB;
 
 	eptp |= (root_level == 5) ? VMX_EPTP_PWL_5 : VMX_EPTP_PWL_4;