From d7adcf1d7fc3af34e1bfe2189542c2d619142986 Mon Sep 17 00:00:00 2001 From: Chenyi Qiang Date: Thu, 4 Mar 2021 18:49:51 -0500 Subject: [PATCH] target/i386: Add bus lock debug exception support Bus lock debug exception is a feature that can notify the kernel by generate an #DB trap after the instruction acquires a bus lock when CPL>0. This allows the kernel to enforce user application throttling or mitigations. This feature is enumerated via CPUID.(EAX=7,ECX=0).ECX[bit 24]. Backports 06e878b413766778a53be3d25c0373a23679d039 --- qemu/target/i386/cpu.c | 2 +- qemu/target/i386/cpu.h | 2 ++ 2 files changed, 3 insertions(+), 1 deletion(-) diff --git a/qemu/target/i386/cpu.c b/qemu/target/i386/cpu.c index 6684c7c6..9d8b3d87 100644 --- a/qemu/target/i386/cpu.c +++ b/qemu/target/i386/cpu.c @@ -861,7 +861,7 @@ static FeatureWordInfo feature_word_info[FEATURE_WORDS] = { "avx512bitalg", NULL, "avx512-vpopcntdq", NULL, "la57", NULL, NULL, NULL, NULL, NULL, "rdpid", NULL, - NULL, "cldemote", NULL, "movdiri", + "bus-lock-detect", "cldemote", NULL, "movdiri", "movdir64b", NULL, NULL, "pks", }, .cpuid = { diff --git a/qemu/target/i386/cpu.h b/qemu/target/i386/cpu.h index 3140f047..f2f758c3 100644 --- a/qemu/target/i386/cpu.h +++ b/qemu/target/i386/cpu.h @@ -714,6 +714,8 @@ typedef uint64_t FeatureWordArray[FEATURE_WORDS]; #define CPUID_7_0_ECX_LA57 (1U << 16) /* Read Processor ID */ #define CPUID_7_0_ECX_RDPID (1U << 22) +/* Bus Lock Debug Exception */ +#define CPUID_7_0_ECX_BUS_LOCK_DETECT (1U << 24) /* Cache Line Demote Instruction */ #define CPUID_7_0_ECX_CLDEMOTE (1U << 25) /* Move Doubleword as Direct Store Instruction */