File 5afc13ae-7-x86-split-X86_FEATURE_SC_MSR.patch of Package xen.7652
# Commit fa9eb09d446a1279f5e861e6b84fa8675dabf148
# Date 2018-05-16 12:19:10 +0100
# Author Andrew Cooper <andrew.cooper3@citrix.com>
# Committer Andrew Cooper <andrew.cooper3@citrix.com>
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@citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
--- sle12sp2.orig/xen/arch/x86/cpu/common.c 2018-05-23 11:13:56.000000000 +0200
+++ sle12sp2/xen/arch/x86/cpu/common.c 2018-05-23 11:16:00.000000000 +0200
@@ -417,9 +417,12 @@ void 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);
--- sle12sp2.orig/xen/arch/x86/spec_ctrl.c 2018-05-23 11:13:56.000000000 +0200
+++ sle12sp2/xen/arch/x86/spec_ctrl.c 2018-05-23 11:16:00.000000000 +0200
@@ -112,7 +112,8 @@ static void __init print_details(enum in
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" : "",
@@ -286,7 +287,8 @@ void __init init_speculation_mitigations
* 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;
--- sle12sp2.orig/xen/include/asm-x86/cpufeature.h 2018-05-23 11:13:56.000000000 +0200
+++ sle12sp2/xen/include/asm-x86/cpufeature.h 2018-05-23 11:16:00.000000000 +0200
@@ -21,12 +21,13 @@ XEN_CPUFEATURE(LFENCE_DISPATCH, (FSCAPIN
XEN_CPUFEATURE(IND_THUNK_LFENCE, (FSCAPINTS+0)*32+ 11) /* Use IND_THUNK_LFENCE */
XEN_CPUFEATURE(IND_THUNK_JMP, (FSCAPINTS+0)*32+ 12) /* Use IND_THUNK_JMP */
XEN_CPUFEATURE(XEN_IBPB, (FSCAPINTS+0)*32+ 13) /* IBRSB || IBPB */
-XEN_CPUFEATURE(SC_MSR, (FSCAPINTS+0)*32+ 14) /* MSR_SPEC_CTRL used by Xen */
+XEN_CPUFEATURE(SC_MSR_PV, (FSCAPINTS+0)*32+ 14) /* MSR_SPEC_CTRL used by Xen for PV */
+XEN_CPUFEATURE(SC_MSR_HVM, (FSCAPINTS+0)*32+ 15) /* MSR_SPEC_CTRL used by Xen for HVM */
XEN_CPUFEATURE(SC_RSB_PV, (FSCAPINTS+0)*32+ 16) /* RSB overwrite needed for PV */
XEN_CPUFEATURE(SC_RSB_HVM, (FSCAPINTS+0)*32+ 17) /* RSB overwrite needed for HVM */
XEN_CPUFEATURE(MFENCE_RDTSC, (FSCAPINTS+0)*32+ 18) /* MFENCE synchronizes RDTSC */
XEN_CPUFEATURE(NO_XPTI, (FSCAPINTS+0)*32+ 19) /* XPTI mitigation not in use */
-XEN_CPUFEATURE(SC_MSR_IDLE, (FSCAPINTS+0)*32+ 20) /* SC_MSR && default_xen_spec_ctrl */
+XEN_CPUFEATURE(SC_MSR_IDLE, (FSCAPINTS+0)*32+ 20) /* (SC_MSR_PV || SC_MSR_HVM) && default_xen_spec_ctrl */
#define NCAPINTS (FSCAPINTS + 1) /* N 32-bit words worth of info */
--- sle12sp2.orig/xen/include/asm-x86/spec_ctrl_asm.h 2018-05-23 11:11:55.000000000 +0200
+++ sle12sp2/xen/include/asm-x86/spec_ctrl_asm.h 2018-05-23 11:16:00.000000000 +0200
@@ -223,36 +223,36 @@
ALTERNATIVE __stringify(ASM_NOP40), \
DO_OVERWRITE_RSB, X86_FEATURE_SC_RSB_HVM; \
ALTERNATIVE __stringify(ASM_NOP36), \
- 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_NOP33), \
- __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_NOP17), \
- 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.
