[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[xen master] x86/spec-ctrl: Enumeration for MMIO Stale Data controls



commit 2ebe8fe9b7e0d36e9ec3cfe4552b2b197ef0dcec
Author:     Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
AuthorDate: Mon Sep 20 18:47:49 2021 +0100
Commit:     Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
CommitDate: Thu Jun 16 12:10:37 2022 +0100

    x86/spec-ctrl: Enumeration for MMIO Stale Data controls
    
    The three *_NO bits indicate non-susceptibility to the SSDP, FBSDP and PSDP
    data movement primitives.
    
    FB_CLEAR indicates that the VERW instruction has re-gained it's Fill Buffer
    flushing side effect.  This is only enumerated on parts where VERW had
    previously lost it's flushing side effect due to the MDS/TAA vulnerabilities
    being fixed in hardware.
    
    FB_CLEAR_CTRL is available on a subset of FB_CLEAR parts where the Fill 
Buffer
    clearing side effect of VERW can be turned off for performance reasons.
    
    This is part of XSA-404.
    
    Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
    Reviewed-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
---
 xen/arch/x86/include/asm/msr-index.h |  6 ++++++
 xen/arch/x86/spec_ctrl.c             | 11 ++++++++---
 2 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/xen/arch/x86/include/asm/msr-index.h 
b/xen/arch/x86/include/asm/msr-index.h
index 6c250bfcad..ea47f68d05 100644
--- a/xen/arch/x86/include/asm/msr-index.h
+++ b/xen/arch/x86/include/asm/msr-index.h
@@ -71,6 +71,11 @@
 #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_SBDR_SSDP_NO             (_AC(1, ULL) << 13)
+#define  ARCH_CAPS_FBSDP_NO                 (_AC(1, ULL) << 14)
+#define  ARCH_CAPS_PSDP_NO                  (_AC(1, ULL) << 15)
+#define  ARCH_CAPS_FB_CLEAR                 (_AC(1, ULL) << 17)
+#define  ARCH_CAPS_FB_CLEAR_CTRL            (_AC(1, ULL) << 18)
 #define  ARCH_CAPS_RRSBA                    (_AC(1, ULL) << 19)
 #define  ARCH_CAPS_BHI_NO                   (_AC(1, ULL) << 20)
 
@@ -90,6 +95,7 @@
 #define  MCU_OPT_CTRL_RNGDS_MITG_DIS        (_AC(1, ULL) <<  0)
 #define  MCU_OPT_CTRL_RTM_ALLOW             (_AC(1, ULL) <<  1)
 #define  MCU_OPT_CTRL_RTM_LOCKED            (_AC(1, ULL) <<  2)
+#define  MCU_OPT_CTRL_FB_CLEAR_DIS          (_AC(1, ULL) <<  3)
 
 #define MSR_RTIT_OUTPUT_BASE                0x00000560
 #define MSR_RTIT_OUTPUT_MASK                0x00000561
diff --git a/xen/arch/x86/spec_ctrl.c b/xen/arch/x86/spec_ctrl.c
index 92eb4ecd3d..2ec3126cf0 100644
--- a/xen/arch/x86/spec_ctrl.c
+++ b/xen/arch/x86/spec_ctrl.c
@@ -323,7 +323,7 @@ static void __init print_details(enum ind_thunk thunk, 
uint64_t caps)
      * Hardware read-only information, stating immunity to certain issues, or
      * suggestions of which mitigation to use.
      */
-    printk("  Hardware hints:%s%s%s%s%s%s%s%s%s%s%s\n",
+    printk("  Hardware hints:%s%s%s%s%s%s%s%s%s%s%s%s%s%s\n",
            (caps & ARCH_CAPS_RDCL_NO)                        ? " RDCL_NO"      
  : "",
            (caps & ARCH_CAPS_IBRS_ALL)                       ? " IBRS_ALL"     
  : "",
            (caps & ARCH_CAPS_RSBA)                           ? " RSBA"         
  : "",
@@ -332,13 +332,16 @@ static void __init print_details(enum ind_thunk thunk, 
uint64_t caps)
            (caps & ARCH_CAPS_SSB_NO)                         ? " SSB_NO"       
  : "",
            (caps & ARCH_CAPS_MDS_NO)                         ? " MDS_NO"       
  : "",
            (caps & ARCH_CAPS_TAA_NO)                         ? " TAA_NO"       
  : "",
+           (caps & ARCH_CAPS_SBDR_SSDP_NO)                   ? " SBDR_SSDP_NO" 
  : "",
+           (caps & ARCH_CAPS_FBSDP_NO)                       ? " FBSDP_NO"     
  : "",
+           (caps & ARCH_CAPS_PSDP_NO)                        ? " PSDP_NO"      
  : "",
            (e8b  & cpufeat_mask(X86_FEATURE_IBRS_ALWAYS))    ? " IBRS_ALWAYS"  
  : "",
            (e8b  & cpufeat_mask(X86_FEATURE_STIBP_ALWAYS))   ? " STIBP_ALWAYS" 
  : "",
            (e8b  & cpufeat_mask(X86_FEATURE_IBRS_FAST))      ? " IBRS_FAST"    
  : "",
            (e8b  & cpufeat_mask(X86_FEATURE_IBRS_SAME_MODE)) ? " 
IBRS_SAME_MODE" : "");
 
     /* Hardware features which need driving to mitigate issues. */
-    printk("  Hardware features:%s%s%s%s%s%s%s%s%s%s\n",
+    printk("  Hardware features:%s%s%s%s%s%s%s%s%s%s%s%s\n",
            (e8b  & cpufeat_mask(X86_FEATURE_IBPB)) ||
            (_7d0 & cpufeat_mask(X86_FEATURE_IBRSB))          ? " IBPB"         
  : "",
            (e8b  & cpufeat_mask(X86_FEATURE_IBRS)) ||
@@ -353,7 +356,9 @@ static void __init print_details(enum ind_thunk thunk, 
uint64_t caps)
            (_7d0 & cpufeat_mask(X86_FEATURE_MD_CLEAR))       ? " MD_CLEAR"     
  : "",
            (_7d0 & cpufeat_mask(X86_FEATURE_SRBDS_CTRL))     ? " SRBDS_CTRL"   
  : "",
            (e8b  & cpufeat_mask(X86_FEATURE_VIRT_SSBD))      ? " VIRT_SSBD"    
  : "",
-           (caps & ARCH_CAPS_TSX_CTRL)                       ? " TSX_CTRL"     
  : "");
+           (caps & ARCH_CAPS_TSX_CTRL)                       ? " TSX_CTRL"     
  : "",
+           (caps & ARCH_CAPS_FB_CLEAR)                       ? " FB_CLEAR"     
  : "",
+           (caps & ARCH_CAPS_FB_CLEAR_CTRL)                  ? " 
FB_CLEAR_CTRL"  : "");
 
     /* Compiled-in support which pertains to mitigations. */
     if ( IS_ENABLED(CONFIG_INDIRECT_THUNK) || IS_ENABLED(CONFIG_SHADOW_PAGING) 
)
--
generated by git-patchbot for /home/xen/git/xen.git#master



 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.