Hello,
Le 20/01/2026 à 10:56, Alejandro Vallejo a écrit :
> Add missing scaffolding to enable BusLock Threshold. That is:
>
> * Add general_intercepts_3.
> * Add missing VMEXIT
> * Adjust NPF perf counter base to immediately after the buslock counter
>
> Signed-off-by: Alejandro Vallejo <[email protected]>
> ---
> xen/arch/x86/hvm/svm/svm.c | 1 +
> xen/arch/x86/hvm/svm/vmcb.h | 15 +++++++++++++--
> xen/arch/x86/include/asm/hvm/svm.h | 2 ++
> xen/arch/x86/include/asm/perfc_defn.h | 2 +-
> 4 files changed, 17 insertions(+), 3 deletions(-)
>
> diff --git a/xen/arch/x86/hvm/svm/svm.c b/xen/arch/x86/hvm/svm/svm.c
> index 5d23603fc1..9748df87d8 100644
> --- a/xen/arch/x86/hvm/svm/svm.c
> +++ b/xen/arch/x86/hvm/svm/svm.c
> @@ -2524,6 +2524,7 @@ const struct hvm_function_table * __init start_svm(void)
> P(cpu_has_tsc_ratio, "TSC Rate MSR");
> P(cpu_has_svm_sss, "NPT Supervisor Shadow Stack");
> P(cpu_has_svm_spec_ctrl, "MSR_SPEC_CTRL virtualisation");
> + P(cpu_has_bus_lock_thresh, "BusLock-Intercept Filter");
> #undef P
>
> if ( !printed )
> diff --git a/xen/arch/x86/hvm/svm/vmcb.h b/xen/arch/x86/hvm/svm/vmcb.h
> index ba554a9644..85e194f247 100644
> --- a/xen/arch/x86/hvm/svm/vmcb.h
> +++ b/xen/arch/x86/hvm/svm/vmcb.h
> @@ -65,6 +65,11 @@ enum GenericIntercept2bits
> GENERAL2_INTERCEPT_RDPRU = 1 << 14,
> };
>
> +/* general 2 intercepts */
nit, you want to says general 3 intercepts
> +enum GenericIntercept3bits
> +{
> + GENERAL3_INTERCEPT_BUS_LOCK_THRESH = 1 << 5,
> +};
>
> /* control register intercepts */
> enum CRInterceptBits
> @@ -289,6 +294,7 @@ enum VMEXIT_EXITCODE
> VMEXIT_MWAIT_CONDITIONAL= 140, /* 0x8c */
> VMEXIT_XSETBV = 141, /* 0x8d */
> VMEXIT_RDPRU = 142, /* 0x8e */
> + VMEXIT_BUSLOCK = 165, /* 0xa5 */
> /* Remember to also update VMEXIT_NPF_PERFC! */
> VMEXIT_NPF = 1024, /* 0x400, nested paging fault */
> /* Remember to also update SVM_PERF_EXIT_REASON_SIZE! */
> @@ -405,7 +411,8 @@ struct vmcb_struct {
> u32 _exception_intercepts; /* offset 0x08 - cleanbit 0 */
> u32 _general1_intercepts; /* offset 0x0C - cleanbit 0 */
> u32 _general2_intercepts; /* offset 0x10 - cleanbit 0 */
> - u32 res01[10];
> + u32 _general3_intercepts; /* offset 0x14 - cleanbit 0 */
> + u32 res01[9];
> u16 _pause_filter_thresh; /* offset 0x3C - cleanbit 0 */
> u16 _pause_filter_count; /* offset 0x3E - cleanbit 0 */
> u64 _iopm_base_pa; /* offset 0x40 - cleanbit 1 */
> @@ -489,7 +496,10 @@ struct vmcb_struct {
> u64 nextrip; /* offset 0xC8 */
> u8 guest_ins_len; /* offset 0xD0 */
> u8 guest_ins[15]; /* offset 0xD1 */
> - u64 res10a[100]; /* offset 0xE0 pad to save area */
> + u64 res10a[8]; /* offset 0xE0 */
> + u16 bus_lock_thresh; /* offset 0x120 */
> + u16 res10b[3]; /* offset 0x122 */
> + u64 res10c[91]; /* offset 0x128 pad to save area */
>
> union {
> struct segment_register sreg[6];
> @@ -583,6 +593,7 @@ VMCB_ACCESSORS(dr_intercepts, intercepts)
> VMCB_ACCESSORS(exception_intercepts, intercepts)
> VMCB_ACCESSORS(general1_intercepts, intercepts)
> VMCB_ACCESSORS(general2_intercepts, intercepts)
> +VMCB_ACCESSORS(general3_intercepts, intercepts)
> VMCB_ACCESSORS(pause_filter_count, intercepts)
> VMCB_ACCESSORS(pause_filter_thresh, intercepts)
> VMCB_ACCESSORS(tsc_offset, intercepts)
> diff --git a/xen/arch/x86/include/asm/hvm/svm.h
> b/xen/arch/x86/include/asm/hvm/svm.h
> index a6d7e4aed3..14fe4abf96 100644
> --- a/xen/arch/x86/include/asm/hvm/svm.h
> +++ b/xen/arch/x86/include/asm/hvm/svm.h
> @@ -37,6 +37,7 @@ extern u32 svm_feature_flags;
> #define SVM_FEATURE_VGIF 16 /* Virtual GIF */
> #define SVM_FEATURE_SSS 19 /* NPT Supervisor Shadow Stacks */
> #define SVM_FEATURE_SPEC_CTRL 20 /* MSR_SPEC_CTRL virtualisation */
> +#define SVM_FEATURE_BUS_LOCK_THRESH 29 /* Bus Lock Threshold */
>
> static inline bool cpu_has_svm_feature(unsigned int feat)
> {
> @@ -56,6 +57,7 @@ static inline bool cpu_has_svm_feature(unsigned int feat)
> #define cpu_has_svm_vloadsave cpu_has_svm_feature(SVM_FEATURE_VLOADSAVE)
> #define cpu_has_svm_sss cpu_has_svm_feature(SVM_FEATURE_SSS)
> #define cpu_has_svm_spec_ctrl cpu_has_svm_feature(SVM_FEATURE_SPEC_CTRL)
> +#define cpu_has_bus_lock_thresh
> cpu_has_svm_feature(SVM_FEATURE_BUS_LOCK_THRESH)
>
> #define MSR_INTERCEPT_NONE 0
> #define MSR_INTERCEPT_READ 1
> diff --git a/xen/arch/x86/include/asm/perfc_defn.h
> b/xen/arch/x86/include/asm/perfc_defn.h
> index d6127cb91e..ac7439b992 100644
> --- a/xen/arch/x86/include/asm/perfc_defn.h
> +++ b/xen/arch/x86/include/asm/perfc_defn.h
> @@ -7,7 +7,7 @@ PERFCOUNTER_ARRAY(exceptions, "exceptions", 32)
> #ifdef CONFIG_HVM
>
> #define VMX_PERF_EXIT_REASON_SIZE 76
> -#define VMEXIT_NPF_PERFC 143
> +#define VMEXIT_NPF_PERFC 166
> #define SVM_PERF_EXIT_REASON_SIZE (VMEXIT_NPF_PERFC + 1)
> PERFCOUNTER_ARRAY(vmexits, "vmexits",
> MAX(VMX_PERF_EXIT_REASON_SIZE, SVM_PERF_EXIT_REASON_SIZE))
With that changed, Reviewed-by: Teddy Astie <[email protected]>
--
Teddy Astie | Vates XCP-ng Developer
XCP-ng & Xen Orchestra - Vates solutions
web: https://vates.tech
