[PATCH 1/1] KVM: VMX: Cleanup VMX basic information defines and usages

From: Xin Li (Intel)
Date: Wed Sep 27 2023 - 19:08:49 EST


From: Xin Li <xin3.li@xxxxxxxxx>

Add IA32_VMX_BASIC MSR bitfield shift macros and use them to define VMX
basic information bitfields.

Add VMX_BASIC_FEATURES and VMX_BASIC_RESERVED_BITS to form a valid bitmask
of IA32_VMX_BASIC MSR. As a result, to add a new VMX basic feature bit,
just change the 2 new macros in the header file.

Also replace hardcoded VMX basic numbers with the new VMX basic macros.

Tested-by: Shan Kang <shan.kang@xxxxxxxxx>
Signed-off-by: Xin Li <xin3.li@xxxxxxxxx>
---
arch/x86/include/asm/msr-index.h | 31 ++++++++++++++++++++------
arch/x86/kvm/vmx/nested.c | 10 +++------
arch/x86/kvm/vmx/vmx.c | 2 +-
tools/arch/x86/include/asm/msr-index.h | 31 ++++++++++++++++++++------
4 files changed, 52 insertions(+), 22 deletions(-)

diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
index 1d111350197f..4607448ff805 100644
--- a/arch/x86/include/asm/msr-index.h
+++ b/arch/x86/include/asm/msr-index.h
@@ -1084,13 +1084,30 @@
#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
+#define VMX_BASIC_VMCS_SIZE_SHIFT 32
+#define VMX_BASIC_ALWAYS_0 BIT_ULL(31)
+#define VMX_BASIC_RESERVED_RANGE_1 GENMASK_ULL(47, 45)
+#define VMX_BASIC_32BIT_PHYS_ADDR_ONLY_SHIFT 48
+#define VMX_BASIC_32BIT_PHYS_ADDR_ONLY BIT_ULL(VMX_BASIC_32BIT_PHYS_ADDR_ONLY_SHIFT)
+#define VMX_BASIC_DUAL_MONITOR_TREATMENT_SHIFT 49
+#define VMX_BASIC_DUAL_MONITOR_TREATMENT BIT_ULL(VMX_BASIC_DUAL_MONITOR_TREATMENT_SHIFT)
+#define VMX_BASIC_MEM_TYPE_SHIFT 50
+#define VMX_BASIC_MEM_TYPE_WB 6LLU
+#define VMX_BASIC_INOUT_SHIFT 54
+#define VMX_BASIC_INOUT BIT_ULL(VMX_BASIC_INOUT_SHIFT)
+#define VMX_BASIC_TRUE_CTLS_SHIFT 55
+#define VMX_BASIC_TRUE_CTLS BIT_ULL(VMX_BASIC_TRUE_CTLS_SHIFT)
+#define VMX_BASIC_RESERVED_RANGE_2 GENMASK_ULL(63, 56)
+
+#define VMX_BASIC_FEATURES \
+ (VMX_BASIC_DUAL_MONITOR_TREATMENT | \
+ VMX_BASIC_INOUT | \
+ VMX_BASIC_TRUE_CTLS)
+
+#define VMX_BASIC_RESERVED_BITS \
+ (VMX_BASIC_ALWAYS_0 | \
+ VMX_BASIC_RESERVED_RANGE_1 | \
+ VMX_BASIC_RESERVED_RANGE_2)

/* Resctrl MSRs: */
/* - Intel: */
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index c5ec0ef51ff7..5280ba944c87 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -1203,21 +1203,17 @@ 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);
u64 vmx_basic = vmcs_config.nested.basic;

- if (!is_bitwise_subset(vmx_basic, data, feature_and_reserved))
+ if (!is_bitwise_subset(vmx_basic, data,
+ VMX_BASIC_FEATURES | 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) !=
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 72e3943f3693..f597243d6a72 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -2701,7 +2701,7 @@ static int setup_vmcs_config(struct vmcs_config *vmcs_conf,

#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 (vmx_msr_high & (1u << (VMX_BASIC_32BIT_PHYS_ADDR_ONLY_SHIFT - 32)))
return -EIO;
#endif

diff --git a/tools/arch/x86/include/asm/msr-index.h b/tools/arch/x86/include/asm/msr-index.h
index 1d111350197f..4607448ff805 100644
--- a/tools/arch/x86/include/asm/msr-index.h
+++ b/tools/arch/x86/include/asm/msr-index.h
@@ -1084,13 +1084,30 @@
#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
+#define VMX_BASIC_VMCS_SIZE_SHIFT 32
+#define VMX_BASIC_ALWAYS_0 BIT_ULL(31)
+#define VMX_BASIC_RESERVED_RANGE_1 GENMASK_ULL(47, 45)
+#define VMX_BASIC_32BIT_PHYS_ADDR_ONLY_SHIFT 48
+#define VMX_BASIC_32BIT_PHYS_ADDR_ONLY BIT_ULL(VMX_BASIC_32BIT_PHYS_ADDR_ONLY_SHIFT)
+#define VMX_BASIC_DUAL_MONITOR_TREATMENT_SHIFT 49
+#define VMX_BASIC_DUAL_MONITOR_TREATMENT BIT_ULL(VMX_BASIC_DUAL_MONITOR_TREATMENT_SHIFT)
+#define VMX_BASIC_MEM_TYPE_SHIFT 50
+#define VMX_BASIC_MEM_TYPE_WB 6LLU
+#define VMX_BASIC_INOUT_SHIFT 54
+#define VMX_BASIC_INOUT BIT_ULL(VMX_BASIC_INOUT_SHIFT)
+#define VMX_BASIC_TRUE_CTLS_SHIFT 55
+#define VMX_BASIC_TRUE_CTLS BIT_ULL(VMX_BASIC_TRUE_CTLS_SHIFT)
+#define VMX_BASIC_RESERVED_RANGE_2 GENMASK_ULL(63, 56)
+
+#define VMX_BASIC_FEATURES \
+ (VMX_BASIC_DUAL_MONITOR_TREATMENT | \
+ VMX_BASIC_INOUT | \
+ VMX_BASIC_TRUE_CTLS)
+
+#define VMX_BASIC_RESERVED_BITS \
+ (VMX_BASIC_ALWAYS_0 | \
+ VMX_BASIC_RESERVED_RANGE_1 | \
+ VMX_BASIC_RESERVED_RANGE_2)

/* Resctrl MSRs: */
/* - Intel: */
--
2.40.1