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| author | Boris Ostrovsky <boris.ostrovsky@oracle.com> | 2015-05-04 11:02:15 -0400 |
|---|---|---|
| committer | David Vrabel <david.vrabel@citrix.com> | 2015-05-05 18:27:43 +0100 |
| commit | a71dbdaa8ca2933391b08e0ae5567083e3af0892 (patch) | |
| tree | ca33c267fb1d81c9f2207e29be17fc4f82235407 /arch/x86/include/asm/hypervisor.h | |
| parent | 16e6bd5970c88a2ac018b84a5f1dd5c2ff1fdf2c (diff) | |
| download | linux-0-day-a71dbdaa8ca2933391b08e0ae5567083e3af0892.tar.gz linux-0-day-a71dbdaa8ca2933391b08e0ae5567083e3af0892.tar.xz | |
hypervisor/x86/xen: Unset X86_BUG_SYSRET_SS_ATTRS on Xen PV guests
Commit 61f01dd941ba ("x86_64, asm: Work around AMD SYSRET SS descriptor
attribute issue") makes AMD processors set SS to __KERNEL_DS in
__switch_to() to deal with cases when SS is NULL.
This breaks Xen PV guests who do not want to load SS with__KERNEL_DS.
Since the problem that the commit is trying to address would have to be
fixed in the hypervisor (if it in fact exists under Xen) there is no
reason to set X86_BUG_SYSRET_SS_ATTRS flag for PV VPCUs here.
This can be easily achieved by adding x86_hyper_xen_hvm.set_cpu_features
op which will clear this flag. (And since this structure is no longer
HVM-specific we should do some renaming).
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reported-by: Sander Eikelenboom <linux@eikelenboom.it>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Diffstat (limited to 'arch/x86/include/asm/hypervisor.h')
| -rw-r--r-- | arch/x86/include/asm/hypervisor.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/include/asm/hypervisor.h b/arch/x86/include/asm/hypervisor.h index e42f758a0fbd9..055ea9941dd5f 100644 --- a/arch/x86/include/asm/hypervisor.h +++ b/arch/x86/include/asm/hypervisor.h @@ -50,7 +50,7 @@ extern const struct hypervisor_x86 *x86_hyper; /* Recognized hypervisors */ extern const struct hypervisor_x86 x86_hyper_vmware; extern const struct hypervisor_x86 x86_hyper_ms_hyperv; -extern const struct hypervisor_x86 x86_hyper_xen_hvm; +extern const struct hypervisor_x86 x86_hyper_xen; extern const struct hypervisor_x86 x86_hyper_kvm; extern void init_hypervisor(struct cpuinfo_x86 *c); |