forked from Minki/linux
a71dbdaa8c
Commit 61f01dd941 ("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>
65 lines
2.0 KiB
C
65 lines
2.0 KiB
C
/*
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* Copyright (C) 2008, VMware, Inc.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
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* NON INFRINGEMENT. See the GNU General Public License for more
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* details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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*/
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#ifndef _ASM_X86_HYPERVISOR_H
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#define _ASM_X86_HYPERVISOR_H
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#ifdef CONFIG_HYPERVISOR_GUEST
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#include <asm/kvm_para.h>
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#include <asm/xen/hypervisor.h>
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/*
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* x86 hypervisor information
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*/
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struct hypervisor_x86 {
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/* Hypervisor name */
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const char *name;
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/* Detection routine */
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uint32_t (*detect)(void);
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/* Adjust CPU feature bits (run once per CPU) */
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void (*set_cpu_features)(struct cpuinfo_x86 *);
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/* Platform setup (run once per boot) */
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void (*init_platform)(void);
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/* X2APIC detection (run once per boot) */
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bool (*x2apic_available)(void);
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};
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extern const struct hypervisor_x86 *x86_hyper;
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/* Recognized hypervisors */
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extern const struct hypervisor_x86 x86_hyper_vmware;
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extern const struct hypervisor_x86 x86_hyper_ms_hyperv;
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extern const struct hypervisor_x86 x86_hyper_xen;
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extern const struct hypervisor_x86 x86_hyper_kvm;
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extern void init_hypervisor(struct cpuinfo_x86 *c);
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extern void init_hypervisor_platform(void);
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extern bool hypervisor_x2apic_available(void);
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#else
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static inline void init_hypervisor(struct cpuinfo_x86 *c) { }
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static inline void init_hypervisor_platform(void) { }
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static inline bool hypervisor_x2apic_available(void) { return false; }
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#endif /* CONFIG_HYPERVISOR_GUEST */
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#endif /* _ASM_X86_HYPERVISOR_H */
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