[PATCH] x86/spec-ctrl: Enumeration for new Intel BHI controls

[PATCH] x86/spec-ctrl: Enumeration for new Intel BHI controls

[Andrew Cooper]

https://www.intel.com/content/www/us/en/developer/articles/technical/software-security-guidance/technical-documentation/branch-history-injection.html

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
---
CC: Jan Beulich <JBeulich@suse.com>
CC: Roger Pau Monné <roger.pau@citrix.com>
CC: Wei Liu <wl@xen.org>

These are defined now, but support in hardware hasn't been released yet.
---
 xen/arch/x86/include/asm/msr-index.h        | 7 +++++++
 xen/include/public/arch-x86/cpufeatureset.h | 3 +++
 2 files changed, 10 insertions(+)

diff --git a/xen/arch/x86/include/asm/msr-index.h b/xen/arch/x86/include/asm/msr-index.h
index 31964b88af7a..6c250bfcadad 100644
--- a/xen/arch/x86/include/asm/msr-index.h
+++ b/xen/arch/x86/include/asm/msr-index.h
@@ -36,7 +36,12 @@
 #define  SPEC_CTRL_IBRS                     (_AC(1, ULL) <<  0)
 #define  SPEC_CTRL_STIBP                    (_AC(1, ULL) <<  1)
 #define  SPEC_CTRL_SSBD                     (_AC(1, ULL) <<  2)
+#define  SPEC_CTRL_IPRED_DIS_U              (_AC(1, ULL) <<  3)
+#define  SPEC_CTRL_IPRED_DIS_S              (_AC(1, ULL) <<  4)
+#define  SPEC_CTRL_RRSBA_DIS_U              (_AC(1, ULL) <<  5)
+#define  SPEC_CTRL_RRSBA_DIS_S              (_AC(1, ULL) <<  6)
 #define  SPEC_CTRL_PSFD                     (_AC(1, ULL) <<  7)
+#define  SPEC_CTRL_BHI_DIS_S                (_AC(1, ULL) << 10)
 
 #define MSR_PRED_CMD                        0x00000049
 #define  PRED_CMD_IBPB                      (_AC(1, ULL) <<  0)
@@ -66,6 +71,8 @@
 #define  ARCH_CAPS_IF_PSCHANGE_MC_NO        (_AC(1, ULL) <<  6)
 #define  ARCH_CAPS_TSX_CTRL                 (_AC(1, ULL) <<  7)
 #define  ARCH_CAPS_TAA_NO                   (_AC(1, ULL) <<  8)
+#define  ARCH_CAPS_RRSBA                    (_AC(1, ULL) << 19)
+#define  ARCH_CAPS_BHI_NO                   (_AC(1, ULL) << 20)
 
 #define MSR_FLUSH_CMD                       0x0000010b
 #define  FLUSH_CMD_L1D                      (_AC(1, ULL) <<  0)
diff --git a/xen/include/public/arch-x86/cpufeatureset.h b/xen/include/public/arch-x86/cpufeatureset.h
index 0c27f5bbaf37..101698941074 100644
--- a/xen/include/public/arch-x86/cpufeatureset.h
+++ b/xen/include/public/arch-x86/cpufeatureset.h
@@ -304,6 +304,9 @@ XEN_CPUFEATURE(INTEL_PPIN,         12*32+ 0) /*   Protected Processor Inventory
 
 /* Intel-defined CPU features, CPUID level 0x00000007:2.edx, word 13 */
 XEN_CPUFEATURE(INTEL_PSFD,         13*32+ 0) /*A  MSR_SPEC_CTRL.PSFD */
+XEN_CPUFEATURE(IPRED_CTRL,         13*32+ 1) /*   MSR_SPEC_CTRL.IPRED_DIS_* */
+XEN_CPUFEATURE(RRSBA_CTRL,         13*32+ 2) /*   MSR_SPEC_CTRL.RRSBA_DIS_* */
+XEN_CPUFEATURE(BHI_CTRL,           13*32+ 4) /*   MSR_SPEC_CTRL.BHI_DIS_S */
 XEN_CPUFEATURE(MCDT_NO,            13*32+ 5) /*A  MCDT_NO */
 
 #endif /* XEN_CPUFEATURE */
-- 
2.11.0

Re: [PATCH] x86/spec-ctrl: Enumeration for new Intel BHI controls

[Jan Beulich]

On 31.05.2022 21:21, Andrew Cooper wrote:
> https://www.intel.com/content/www/us/en/developer/articles/technical/software-security-guidance/technical-documentation/branch-history-injection.html
> 
> Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Reviewed-by: Jan Beulich <jbeulich@suse.com>