| Message ID | 20210202090224.13274-1-chenyi.qiang@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | target/i386: Add bus lock debug exception support | expand |
On 02/02/21 10:02, Chenyi Qiang wrote: > 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]. > > Signed-off-by: Chenyi Qiang <chenyi.qiang@intel.com> > --- > target/i386/cpu.c | 2 +- > target/i386/cpu.h | 2 ++ > 2 files changed, 3 insertions(+), 1 deletion(-) > > diff --git a/target/i386/cpu.c b/target/i386/cpu.c > index ae89024d36..55f3b5829f 100644 > --- a/target/i386/cpu.c > +++ b/target/i386/cpu.c > @@ -963,7 +963,7 @@ 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, NULL, > }, > .cpuid = { > diff --git a/target/i386/cpu.h b/target/i386/cpu.h > index d23a5b340a..417f49b721 100644 > --- a/target/i386/cpu.h > +++ b/target/i386/cpu.h > @@ -762,6 +762,8 @@ 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 */ > Queued, thanks. Paolo
diff --git a/target/i386/cpu.c b/target/i386/cpu.c index ae89024d36..55f3b5829f 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -963,7 +963,7 @@ 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, NULL, }, .cpuid = { diff --git a/target/i386/cpu.h b/target/i386/cpu.h index d23a5b340a..417f49b721 100644 --- a/target/i386/cpu.h +++ b/target/i386/cpu.h @@ -762,6 +762,8 @@ 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 */
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]. Signed-off-by: Chenyi Qiang <chenyi.qiang@intel.com> --- target/i386/cpu.c | 2 +- target/i386/cpu.h | 2 ++ 2 files changed, 3 insertions(+), 1 deletion(-)