qemu-kvm/SOURCES/kvm-target-i386-Enable-fdp-excptn-only-and-zero-fcs-fds.patch

76 lines
3.1 KiB
Diff

From d6c70ced910aede72d11b6a698bfda9648a3c959 Mon Sep 17 00:00:00 2001
From: Paolo Bonzini <pbonzini@redhat.com>
Date: Fri, 18 Jul 2025 18:03:43 +0200
Subject: [PATCH 002/115] target/i386: Enable fdp-excptn-only and zero-fcs-fds
RH-Author: Paolo Bonzini <pbonzini@redhat.com>
RH-MergeRequest: 391: TDX support, including attestation and device assignment
RH-Jira: RHEL-15710 RHEL-20798 RHEL-49728
RH-Acked-by: Yash Mankad <None>
RH-Acked-by: Peter Xu <peterx@redhat.com>
RH-Acked-by: David Hildenbrand <david@redhat.com>
RH-Commit: [2/115] 58b986eab9ccc86b3f50ca480ae184779cd85bee (bonzini/rhel-qemu-kvm)
- CPUID.(EAX=07H,ECX=0H):EBX[bit 6]: x87 FPU Data Pointer updated only
on x87 exceptions if 1.
- CPUID.(EAX=07H,ECX=0H):EBX[bit 13]: Deprecates FPU CS and FPU DS
values if 1. i.e., X87 FCS and FDS are always zero.
Define names for them so that they can be exposed to guest with -cpu host.
Also define the bit field MACROs so that named cpu models can add it as
well in the future.
Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
Link: https://lore.kernel.org/r/20240814075431.339209-3-xiaoyao.li@intel.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit 7dddc3bb875e7141ab25931d0f30a1c319bc8457)
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
target/i386/cpu.c | 4 ++--
target/i386/cpu.h | 4 ++++
2 files changed, 6 insertions(+), 2 deletions(-)
diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index 0ac6cd8ad7..1fe492f33d 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -1058,9 +1058,9 @@ FeatureWordInfo feature_word_info[FEATURE_WORDS] = {
.type = CPUID_FEATURE_WORD,
.feat_names = {
"fsgsbase", "tsc-adjust", "sgx", "bmi1",
- "hle", "avx2", NULL, "smep",
+ "hle", "avx2", "fdp-excptn-only", "smep",
"bmi2", "erms", "invpcid", "rtm",
- NULL, NULL, "mpx", NULL,
+ NULL, "zero-fcs-fds", "mpx", NULL,
"avx512f", "avx512dq", "rdseed", "adx",
"smap", "avx512ifma", "pcommit", "clflushopt",
"clwb", "intel-pt", "avx512pf", "avx512er",
diff --git a/target/i386/cpu.h b/target/i386/cpu.h
index e513e5f62d..5924761551 100644
--- a/target/i386/cpu.h
+++ b/target/i386/cpu.h
@@ -828,6 +828,8 @@ uint64_t x86_cpu_get_supported_feature_word(X86CPU *cpu, FeatureWord w);
#define CPUID_7_0_EBX_HLE (1U << 4)
/* Intel Advanced Vector Extensions 2 */
#define CPUID_7_0_EBX_AVX2 (1U << 5)
+/* FPU data pointer updated only on x87 exceptions */
+#define CPUID_7_0_EBX_FDP_EXCPTN_ONLY (1u << 6)
/* Supervisor-mode Execution Prevention */
#define CPUID_7_0_EBX_SMEP (1U << 7)
/* 2nd Group of Advanced Bit Manipulation Extensions */
@@ -838,6 +840,8 @@ uint64_t x86_cpu_get_supported_feature_word(X86CPU *cpu, FeatureWord w);
#define CPUID_7_0_EBX_INVPCID (1U << 10)
/* Restricted Transactional Memory */
#define CPUID_7_0_EBX_RTM (1U << 11)
+/* Zero out FPU CS and FPU DS */
+#define CPUID_7_0_EBX_ZERO_FCS_FDS (1U << 13)
/* Memory Protection Extension */
#define CPUID_7_0_EBX_MPX (1U << 14)
/* AVX-512 Foundation */
--
2.50.1