File 62f27ebd-x86-expose-more-MSR_ARCH_CAPS-to-hwdom... of Package xen.28171

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File 62f27ebd-x86-expose-more-MSR_ARCH_CAPS-to-hwdom.patch of Package xen.28171

# Commit e83cd54611fec5b7a539fa1281a14319143490e6
# Date 2022-08-09 16:35:25 +0100
# Author Jason Andryuk <jandryuk@gmail.com>
# Committer Andrew Cooper <andrew.cooper3@citrix.com>
x86: Expose more MSR_ARCH_CAPS to hwdom

commit e46474278a0e ("x86/intel: Expose MSR_ARCH_CAPS to dom0") started
exposing MSR_ARCH_CAPS to dom0.  More bits in MSR_ARCH_CAPS have since
been defined, but they haven't been exposed.  Update the list to allow
them through.

As one example, this allows a Linux Dom0 to know that it has the
appropriate microcode via FB_CLEAR.  Notably, and with the updated
microcode, this changes dom0's
/sys/devices/system/cpu/vulnerabilities/mmio_stale_data changes from:

"Vulnerable: Clear CPU buffers attempted, no microcode; SMT Host state unknown"

to:

"Mitigation: Clear CPU buffers; SMT Host state unknown"

This exposes the MMIO Stale Data and Intel Branch History Injection
(BHI) controls as well as the page size change MCE issue bit.

Fixes: commit 2ebe8fe9b7e0 ("x86/spec-ctrl: Enumeration for MMIO Stale Data controls")
Fixes: commit cea9ae062295 ("x86/spec-ctrl: Enumeration for new Intel BHI controls")
Fixes: commit 59e89cdabc71 ("x86/vtx: Disable executable EPT superpages to work around CVE-2018-12207")
Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>

--- a/xen/arch/x86/msr.c
+++ b/xen/arch/x86/msr.c
@@ -144,7 +144,10 @@ int init_domain_msr_policy(struct domain
 
         mp->arch_caps.raw = val &
             (ARCH_CAPS_RDCL_NO | ARCH_CAPS_IBRS_ALL | ARCH_CAPS_RSBA |
-             ARCH_CAPS_SSB_NO | ARCH_CAPS_MDS_NO | ARCH_CAPS_TAA_NO);
+             ARCH_CAPS_SSB_NO | ARCH_CAPS_MDS_NO | ARCH_CAPS_IF_PSCHANGE_MC_NO |
+             ARCH_CAPS_TAA_NO | ARCH_CAPS_SBDR_SSDP_NO | ARCH_CAPS_FBSDP_NO |
+             ARCH_CAPS_PSDP_NO | ARCH_CAPS_FB_CLEAR | ARCH_CAPS_RRSBA |
+             ARCH_CAPS_BHI_NO);
     }
 
     d->arch.msr = mp;
--- a/xen/include/asm-x86/msr-index.h
+++ b/xen/include/asm-x86/msr-index.h
@@ -61,6 +61,8 @@
 #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)
 
 #define MSR_FLUSH_CMD                       0x0000010b
 #define  FLUSH_CMD_L1D                      (_AC(1, ULL) <<  0)

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File 62f27ebd-x86-expose-more-MSR_ARCH_CAPS-to-hwdom.patch of Package xen.28171

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