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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-changelog] [xen staging-4.6] x86/spec_ctrl: Split X86_FEATURE_SC_MSR into PV and HVM variants
commit 2d8e87ecf89a1f2ac07f563d2c6f620730394db5
Author: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
AuthorDate: Tue May 29 11:00:29 2018 +0200
Commit: Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Tue May 29 11:00:29 2018 +0200
x86/spec_ctrl: Split X86_FEATURE_SC_MSR into PV and HVM variants
In order to separately control whether MSR_SPEC_CTRL is virtualised for PV
and
HVM guests, split the feature used to control runtime alternatives into two.
Xen will use MSR_SPEC_CTRL itself if either of these features are active.
Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
Reviewed-by: Wei Liu <wei.liu2@xxxxxxxxxx>
Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
master commit: fa9eb09d446a1279f5e861e6b84fa8675dabf148
master date: 2018-05-16 12:19:10 +0100
---
xen/arch/x86/cpu/common.c | 7 +++++--
xen/arch/x86/spec_ctrl.c | 6 ++++--
xen/include/asm-x86/cpufeature.h | 5 +++--
xen/include/asm-x86/spec_ctrl_asm.h | 12 ++++++------
4 files changed, 18 insertions(+), 12 deletions(-)
diff --git a/xen/arch/x86/cpu/common.c b/xen/arch/x86/cpu/common.c
index 15e831abde..0e8fd2e74d 100644
--- a/xen/arch/x86/cpu/common.c
+++ b/xen/arch/x86/cpu/common.c
@@ -359,9 +359,12 @@ void __cpuinit identify_cpu(struct cpuinfo_x86 *c)
if (test_bit(X86_FEATURE_IND_THUNK_JMP,
boot_cpu_data.x86_capability))
__set_bit(X86_FEATURE_IND_THUNK_JMP, c->x86_capability);
- if (test_bit(X86_FEATURE_SC_MSR,
+ if (test_bit(X86_FEATURE_SC_MSR_PV,
boot_cpu_data.x86_capability))
- __set_bit(X86_FEATURE_SC_MSR, c->x86_capability);
+ __set_bit(X86_FEATURE_SC_MSR_PV, c->x86_capability);
+ if (test_bit(X86_FEATURE_SC_MSR_HVM,
+ boot_cpu_data.x86_capability))
+ __set_bit(X86_FEATURE_SC_MSR_HVM, c->x86_capability);
if (test_bit(X86_FEATURE_SC_RSB_PV,
boot_cpu_data.x86_capability))
__set_bit(X86_FEATURE_SC_RSB_PV, c->x86_capability);
diff --git a/xen/arch/x86/spec_ctrl.c b/xen/arch/x86/spec_ctrl.c
index 778f8e5833..fece1056b9 100644
--- a/xen/arch/x86/spec_ctrl.c
+++ b/xen/arch/x86/spec_ctrl.c
@@ -114,7 +114,8 @@ static void __init print_details(enum ind_thunk thunk,
uint64_t caps)
thunk == THUNK_RETPOLINE ? "RETPOLINE" :
thunk == THUNK_LFENCE ? "LFENCE" :
thunk == THUNK_JMP ? "JMP" : "?",
- boot_cpu_has(X86_FEATURE_SC_MSR) ?
+ (boot_cpu_has(X86_FEATURE_SC_MSR_PV) ||
+ boot_cpu_has(X86_FEATURE_SC_MSR_HVM)) ?
default_xen_spec_ctrl & SPEC_CTRL_IBRS ? " IBRS+" :
" IBRS-" : "",
opt_ibpb ? " IBPB" : "",
@@ -283,7 +284,8 @@ void __init init_speculation_mitigations(void)
* need the IBRS entry/exit logic to virtualise IBRS support for
* guests.
*/
- __set_bit(X86_FEATURE_SC_MSR, boot_cpu_data.x86_capability);
+ __set_bit(X86_FEATURE_SC_MSR_PV, boot_cpu_data.x86_capability);
+ __set_bit(X86_FEATURE_SC_MSR_HVM, boot_cpu_data.x86_capability);
if ( ibrs )
default_xen_spec_ctrl |= SPEC_CTRL_IBRS;
diff --git a/xen/include/asm-x86/cpufeature.h b/xen/include/asm-x86/cpufeature.h
index d140982708..3aaa6c8078 100644
--- a/xen/include/asm-x86/cpufeature.h
+++ b/xen/include/asm-x86/cpufeature.h
@@ -65,7 +65,8 @@
#define X86_FEATURE_IND_THUNK_LFENCE (3*32+ 1) /* Use IND_THUNK_LFENCE */
#define X86_FEATURE_IND_THUNK_JMP (3*32+ 2) /* Use IND_THUNK_JMP */
#define X86_FEATURE_XEN_IBPB (3*32+ 3) /* IBRSB || IBPB */
-#define X86_FEATURE_SC_MSR (3*32+ 4) /* MSR_SPEC_CTRL used by Xen */
+#define X86_FEATURE_SC_MSR_PV (3*32+ 4) /* MSR_SPEC_CTRL used by Xen for
PV */
+#define X86_FEATURE_SC_MSR_HVM (3*32+ 5) /* MSR_SPEC_CTRL used by Xen for
HVM */
#define X86_FEATURE_SC_RSB_PV (3*32+ 6) /* RSB overwrite needed for PV */
#define X86_FEATURE_SC_RSB_HVM (3*32+ 7) /* RSB overwrite needed for HVM
*/
#define X86_FEATURE_CONSTANT_TSC (3*32+ 8) /* TSC ticks at a constant rate */
@@ -76,7 +77,7 @@
#define X86_FEATURE_XTOPOLOGY (3*32+13) /* cpu topology enum extensions */
#define X86_FEATURE_CPUID_FAULTING (3*32+14) /* cpuid faulting */
#define X86_FEATURE_CLFLUSH_MONITOR (3*32+15) /* clflush reqd with monitor */
-#define X86_FEATURE_SC_MSR_IDLE (3*32+16) /* SC_MSR &&
default_xen_spec_ctrl */
+#define X86_FEATURE_SC_MSR_IDLE (3*32+16) /* (SC_MSR_PV || SC_MSR_HVM) &&
default_xen_spec_ctrl */
/* Intel-defined CPU features, CPUID level 0x00000001 (ecx), word 4 */
#define X86_FEATURE_XMM3 (4*32+ 0) /* Streaming SIMD Extensions-3 */
diff --git a/xen/include/asm-x86/spec_ctrl_asm.h
b/xen/include/asm-x86/spec_ctrl_asm.h
index be5cba318e..30077d71fb 100644
--- a/xen/include/asm-x86/spec_ctrl_asm.h
+++ b/xen/include/asm-x86/spec_ctrl_asm.h
@@ -223,36 +223,36 @@
ALTERNATIVE __stringify(ASM_NOP40), \
DO_OVERWRITE_RSB, X86_FEATURE_SC_RSB_HVM; \
ALTERNATIVE __stringify(ASM_NOP33), \
- DO_SPEC_CTRL_ENTRY_FROM_HVM, X86_FEATURE_SC_MSR
+ DO_SPEC_CTRL_ENTRY_FROM_HVM, X86_FEATURE_SC_MSR_HVM
/* Use after an entry from PV context (syscall/sysenter/int80/int82/etc). */
#define SPEC_CTRL_ENTRY_FROM_PV \
ALTERNATIVE __stringify(ASM_NOP40), \
DO_OVERWRITE_RSB, X86_FEATURE_SC_RSB_PV; \
ALTERNATIVE __stringify(ASM_NOP25), \
- __stringify(DO_SPEC_CTRL_ENTRY maybexen=0), X86_FEATURE_SC_MSR
+ __stringify(DO_SPEC_CTRL_ENTRY maybexen=0), X86_FEATURE_SC_MSR_PV
/* Use in interrupt/exception context. May interrupt Xen or PV context. */
#define SPEC_CTRL_ENTRY_FROM_INTR \
ALTERNATIVE __stringify(ASM_NOP40), \
DO_OVERWRITE_RSB, X86_FEATURE_SC_RSB_PV; \
ALTERNATIVE __stringify(ASM_NOP39), \
- __stringify(DO_SPEC_CTRL_ENTRY maybexen=1), X86_FEATURE_SC_MSR
+ __stringify(DO_SPEC_CTRL_ENTRY maybexen=1), X86_FEATURE_SC_MSR_PV
/* Use when exiting to Xen context. */
#define SPEC_CTRL_EXIT_TO_XEN \
ALTERNATIVE __stringify(ASM_NOP23), \
- DO_SPEC_CTRL_EXIT_TO_XEN, X86_FEATURE_SC_MSR
+ DO_SPEC_CTRL_EXIT_TO_XEN, X86_FEATURE_SC_MSR_PV
/* Use when exiting to PV guest context. */
#define SPEC_CTRL_EXIT_TO_PV \
ALTERNATIVE __stringify(ASM_NOP24), \
- DO_SPEC_CTRL_EXIT_TO_GUEST, X86_FEATURE_SC_MSR
+ DO_SPEC_CTRL_EXIT_TO_GUEST, X86_FEATURE_SC_MSR_PV
/* Use when exiting to HVM guest context. */
#define SPEC_CTRL_EXIT_TO_HVM \
ALTERNATIVE __stringify(ASM_NOP24), \
- DO_SPEC_CTRL_EXIT_TO_GUEST, X86_FEATURE_SC_MSR
+ DO_SPEC_CTRL_EXIT_TO_GUEST, X86_FEATURE_SC_MSR_HVM
/*
* Use in IST interrupt/exception context. May interrupt Xen or PV context.
--
generated by git-patchbot for /home/xen/git/xen.git#staging-4.6
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