qemu-kvm/kvm-target-i386-Add-feature-dependencies-for-AVX10.patch

From c44f6f57898eb9f382545201033586a17bbde83c Mon Sep 17 00:00:00 2001
From: Tao Su <tao1.su@linux.intel.com>
Date: Thu, 31 Oct 2024 16:52:31 +0800
Subject: [PATCH 35/38] target/i386: Add feature dependencies for AVX10

RH-Author: Paolo Bonzini <pbonzini@redhat.com>
RH-MergeRequest: 280: Add support for the AVX10.1, SHA512, SM3 and SM4 instruction sets
RH-Jira: RHEL-30315 RHEL-45110
RH-Acked-by: Vitaly Kuznetsov <vkuznets@redhat.com>
RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>
RH-Commit: [6/9] 38b1a79032d7acdb264a6403fd4d8239d89b68c4 (bonzini/rhel-qemu-kvm)

Since the highest supported vector length for a processor implies that
all lesser vector lengths are also supported, add the dependencies of
the supported vector lengths. If all vector lengths aren't supported,
clear AVX10 enable bit as well.

Note that the order of AVX10 related dependencies should be kept as:
        CPUID_24_0_EBX_AVX10_128     -> CPUID_24_0_EBX_AVX10_256,
        CPUID_24_0_EBX_AVX10_256     -> CPUID_24_0_EBX_AVX10_512,
        CPUID_24_0_EBX_AVX10_VL_MASK -> CPUID_7_1_EDX_AVX10,
        CPUID_7_1_EDX_AVX10          -> CPUID_24_0_EBX,
so that prevent user from setting weird CPUID combinations, e.g. 256-bits
and 512-bits are supported but 128-bits is not, no vector lengths are
supported but AVX10 enable bit is still set.

Since AVX10_128 will be reserved as 1, adding these dependencies has the
bonus that when user sets -cpu host,-avx10-128, CPUID_7_1_EDX_AVX10 and
CPUID_24_0_EBX will be disabled automatically.

Tested-by: Xuelian Guo <xuelian.guo@intel.com>
Signed-off-by: Tao Su <tao1.su@linux.intel.com>
Link: https://lore.kernel.org/r/20241028024512.156724-5-tao1.su@linux.intel.com
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Link: https://lore.kernel.org/r/20241031085233.425388-7-tao1.su@linux.intel.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit 150ab84b2d0083e6af344cca70290614d4fe568d)
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 target/i386/cpu.c | 16 ++++++++++++++++
 target/i386/cpu.h |  4 ++++
 2 files changed, 20 insertions(+)

diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index 958cbff54d..a740429fdd 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -1766,6 +1766,22 @@ static FeatureDep feature_dependencies[] = {
         .from = { FEAT_7_0_EBX,             CPUID_7_0_EBX_SGX },
         .to = { FEAT_SGX_12_1_EAX,          ~0ull },
     },
+    {
+        .from = { FEAT_24_0_EBX,            CPUID_24_0_EBX_AVX10_128 },
+        .to = { FEAT_24_0_EBX,              CPUID_24_0_EBX_AVX10_256 },
+    },
+    {
+        .from = { FEAT_24_0_EBX,            CPUID_24_0_EBX_AVX10_256 },
+        .to = { FEAT_24_0_EBX,              CPUID_24_0_EBX_AVX10_512 },
+    },
+    {
+        .from = { FEAT_24_0_EBX,            CPUID_24_0_EBX_AVX10_VL_MASK },
+        .to = { FEAT_7_1_EDX,               CPUID_7_1_EDX_AVX10 },
+    },
+    {
+        .from = { FEAT_7_1_EDX,             CPUID_7_1_EDX_AVX10 },
+        .to = { FEAT_24_0_EBX,              ~0ull },
+    },
 };
 
 typedef struct X86RegisterInfo32 {
diff --git a/target/i386/cpu.h b/target/i386/cpu.h
index c60290b8d5..4da9ed5930 100644
--- a/target/i386/cpu.h
+++ b/target/i386/cpu.h
@@ -997,6 +997,10 @@ uint64_t x86_cpu_get_supported_feature_word(X86CPU *cpu, FeatureWord w);
 #define CPUID_24_0_EBX_AVX10_256        (1U << 17)
 /* AVX10 512-bit vector support is present */
 #define CPUID_24_0_EBX_AVX10_512        (1U << 18)
+/* AVX10 vector length support mask */
+#define CPUID_24_0_EBX_AVX10_VL_MASK    (CPUID_24_0_EBX_AVX10_128 | \
+                                         CPUID_24_0_EBX_AVX10_256 | \
+                                         CPUID_24_0_EBX_AVX10_512)
 
 /* RAS Features */
 #define CPUID_8000_0007_EBX_OVERFLOW_RECOV    (1U << 0)
-- 
2.39.3