diff options
| author | Juergen Gross <jgross@suse.com> | 2018-02-26 15:08:18 +0100 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2018-06-16 22:22:30 +0100 |
| commit | 69992a0ace74c52c41e63ff98e49dde44bd2d178 (patch) | |
| tree | 1a6e43ef7858ff0dbe4f32a04a0c2c20715ef74b | |
| parent | 68989898005a788045b696264e678af4816868e3 (diff) | |
| download | linux-stable-69992a0ace74c52c41e63ff98e49dde44bd2d178.tar.gz linux-stable-69992a0ace74c52c41e63ff98e49dde44bd2d178.tar.bz2 linux-stable-69992a0ace74c52c41e63ff98e49dde44bd2d178.zip | |
x86/xen: Zero MSR_IA32_SPEC_CTRL before suspend
commit 71c208dd54ab971036d83ff6d9837bae4976e623 upstream.
Older Xen versions (4.5 and before) might have problems migrating pv
guests with MSR_IA32_SPEC_CTRL having a non-zero value. So before
suspending zero that MSR and restore it after being resumed.
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Cc: xen-devel@lists.xenproject.org
Cc: boris.ostrovsky@oracle.com
Link: https://lkml.kernel.org/r/20180226140818.4849-1-jgross@suse.com
[bwh: Backported to 3.16:
- Include <asm/cpufeature.h> instead of <asm/cpufeatures.h>
- Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
| -rw-r--r-- | arch/x86/xen/suspend.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/arch/x86/xen/suspend.c b/arch/x86/xen/suspend.c index e88330600ca4..e37ae1c74d2b 100644 --- a/arch/x86/xen/suspend.c +++ b/arch/x86/xen/suspend.c @@ -1,10 +1,13 @@ #include <linux/types.h> #include <linux/clockchips.h> +#include <linux/percpu-defs.h> #include <xen/interface/xen.h> #include <xen/grant_table.h> #include <xen/events.h> +#include <asm/cpufeature.h> +#include <asm/msr-index.h> #include <asm/xen/hypercall.h> #include <asm/xen/page.h> #include <asm/fixmap.h> @@ -12,6 +15,8 @@ #include "xen-ops.h" #include "mmu.h" +static DEFINE_PER_CPU(u64, spec_ctrl); + static void xen_pv_pre_suspend(void) { xen_mm_pin_all(); @@ -84,6 +89,9 @@ static void xen_vcpu_notify_restore(void *data) { unsigned long reason = (unsigned long)data; + if (xen_pv_domain() && boot_cpu_has(X86_FEATURE_SPEC_CTRL)) + wrmsrl(MSR_IA32_SPEC_CTRL, this_cpu_read(spec_ctrl)); + /* Boot processor notified via generic timekeeping_resume() */ if ( smp_processor_id() == 0) return; @@ -93,6 +101,13 @@ static void xen_vcpu_notify_restore(void *data) static void xen_vcpu_notify_suspend(void *data) { + u64 tmp; + + if (xen_pv_domain() && boot_cpu_has(X86_FEATURE_SPEC_CTRL)) { + rdmsrl(MSR_IA32_SPEC_CTRL, tmp); + this_cpu_write(spec_ctrl, tmp); + wrmsrl(MSR_IA32_SPEC_CTRL, 0); + } } void xen_arch_resume(void) |