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[PATCH 1/4] target/i386/cpu: Remove unnecessary SGX feature words checks
From: |
Zhao Liu |
Subject: |
[PATCH 1/4] target/i386/cpu: Remove unnecessary SGX feature words checks |
Date: |
Tue, 30 Jul 2024 12:55:41 +0800 |
CPUID.0x7.0.ebx and CPUID.0x7.0.ecx leaves have been expressed as the
feature word lists, and the Host capability support has been checked
in x86_cpu_filter_features().
Therefore, such checks on SGX feature "words" are redundant, and
the follow-up adjustments to those feature "words" will not actually
take effect.
Remove unnecessary SGX feature words related checks.
Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
---
target/i386/cpu.c | 16 +---------------
1 file changed, 1 insertion(+), 15 deletions(-)
diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index 4688d140c2d9..2b3642c9b13c 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -6537,8 +6537,6 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index,
uint32_t count,
case 7:
/* Structured Extended Feature Flags Enumeration Leaf */
if (count == 0) {
- uint32_t eax_0_unused, ebx_0, ecx_0, edx_0_unused;
-
/* Maximum ECX value for sub-leaves */
*eax = env->cpuid_level_func7;
*ebx = env->features[FEAT_7_0_EBX]; /* Feature flags */
@@ -6548,20 +6546,8 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index,
uint32_t count,
}
*edx = env->features[FEAT_7_0_EDX]; /* Feature flags */
- /*
- * SGX cannot be emulated in software. If hardware does not
- * support enabling SGX and/or SGX flexible launch control,
- * then we need to update the VM's CPUID values accordingly.
- */
- x86_cpu_get_supported_cpuid(0x7, 0,
- &eax_0_unused, &ebx_0,
- &ecx_0, &edx_0_unused);
- if ((*ebx & CPUID_7_0_EBX_SGX) && !(ebx_0 & CPUID_7_0_EBX_SGX)) {
- *ebx &= ~CPUID_7_0_EBX_SGX;
- }
-
if ((*ecx & CPUID_7_0_ECX_SGX_LC)
- && (!(*ebx & CPUID_7_0_EBX_SGX) || !(ecx_0 &
CPUID_7_0_ECX_SGX_LC))) {
+ && (!(*ebx & CPUID_7_0_EBX_SGX))) {
*ecx &= ~CPUID_7_0_ECX_SGX_LC;
}
} else if (count == 1) {
--
2.34.1
- [PATCH 0/4] i386: Clean up SGX for microvm, completely, Zhao Liu, 2024/07/30
- [PATCH 1/4] target/i386/cpu: Remove unnecessary SGX feature words checks,
Zhao Liu <=
- [PATCH 2/4] target/i386/cpu: Explicitly express SGX_LC and SGX feature words dependency, Zhao Liu, 2024/07/30
- [PATCH 3/4] target/i386/cpu: Add dependencies of CPUID 0x12 leaves, Zhao Liu, 2024/07/30
- [PATCH 4/4] target/i386/cpu: Mask off SGX/SGX_LC feature words for non-PC machine, Zhao Liu, 2024/07/30
- Re: [PATCH 0/4] i386: Clean up SGX for microvm, completely, Paolo Bonzini, 2024/07/30