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From 5efcae1eb30ff24e100954e00889a568c1745ea1 Mon Sep 17 00:00:00 2001
From: Jason Andryuk <jandryuk@gmail.com>
Date: Mon, 15 Aug 2022 15:40:47 +0200
Subject: [PATCH 34/67] 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>
master commit: e83cd54611fec5b7a539fa1281a14319143490e6
master date: 2022-08-09 16:35:25 +0100
---
xen/arch/x86/msr.c | 5 ++++-
xen/include/asm-x86/msr-index.h | 2 ++
2 files changed, 6 insertions(+), 1 deletion(-)
diff --git a/xen/arch/x86/msr.c b/xen/arch/x86/msr.c
index 0739d00e74f1..aa9face9aad3 100644
--- a/xen/arch/x86/msr.c
+++ b/xen/arch/x86/msr.c
@@ -145,7 +145,10 @@ int init_domain_msr_policy(struct domain *d)
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;
diff --git a/xen/include/asm-x86/msr-index.h b/xen/include/asm-x86/msr-index.h
index f1b2cf5460c1..49ca1f1845e6 100644
--- a/xen/include/asm-x86/msr-index.h
+++ b/xen/include/asm-x86/msr-index.h
@@ -64,6 +64,8 @@
#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)
--
2.37.3
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