diff options
| author | Andy Lutomirski <luto@kernel.org> | 2016-04-02 07:01:38 -0700 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-04-13 11:37:46 +0200 |
| commit | dd2f4a004b016bbfb64f1de49cb45e66232e40a6 (patch) | |
| tree | 8c95610aa558cd7c257c08608c063dec10c9f215 /arch/x86/include | |
| parent | fbd704374d111bed16a19261176fa30e2379c87c (diff) | |
| download | linux-dd2f4a004b016bbfb64f1de49cb45e66232e40a6.tar.bz2 | |
x86/paravirt: Add paravirt_{read,write}_msr()
This adds paravirt callbacks for unsafe MSR access. On native, they
call native_{read,write}_msr(). On Xen, they use xen_{read,write}_msr_safe().
Nothing uses them yet for ease of bisection. The next patch will
use them in rdmsrl(), wrmsrl(), etc.
I intentionally didn't make them warn on #GP on Xen. I think that
should be done separately by the Xen maintainers.
Tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: KVM list <kvm@vger.kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: xen-devel <Xen-devel@lists.xen.org>
Link: http://lkml.kernel.org/r/880eebc5dcd2ad9f310d41345f82061ea500e9fa.1459605520.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/include')
| -rw-r--r-- | arch/x86/include/asm/msr.h | 5 | ||||
| -rw-r--r-- | arch/x86/include/asm/paravirt.h | 11 | ||||
| -rw-r--r-- | arch/x86/include/asm/paravirt_types.h | 10 |
3 files changed, 22 insertions, 4 deletions
diff --git a/arch/x86/include/asm/msr.h b/arch/x86/include/asm/msr.h index 25f169c6eb95..00050c034a13 100644 --- a/arch/x86/include/asm/msr.h +++ b/arch/x86/include/asm/msr.h @@ -111,8 +111,9 @@ static inline unsigned long long native_read_msr_safe(unsigned int msr, return EAX_EDX_VAL(val, low, high); } -static inline void native_write_msr(unsigned int msr, - unsigned low, unsigned high) +/* Can be uninlined because referenced by paravirt */ +notrace static inline void native_write_msr(unsigned int msr, + unsigned low, unsigned high) { asm volatile("1: wrmsr\n" "2:\n" diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h index 81ef2d5c2a24..97839fa8b8aa 100644 --- a/arch/x86/include/asm/paravirt.h +++ b/arch/x86/include/asm/paravirt.h @@ -130,6 +130,17 @@ static inline void wbinvd(void) #define get_kernel_rpl() (pv_info.kernel_rpl) +static inline u64 paravirt_read_msr(unsigned msr) +{ + return PVOP_CALL1(u64, pv_cpu_ops.read_msr, msr); +} + +static inline void paravirt_write_msr(unsigned msr, + unsigned low, unsigned high) +{ + return PVOP_VCALL3(pv_cpu_ops.write_msr, msr, low, high); +} + static inline u64 paravirt_read_msr_safe(unsigned msr, int *err) { return PVOP_CALL2(u64, pv_cpu_ops.read_msr_safe, msr, err); diff --git a/arch/x86/include/asm/paravirt_types.h b/arch/x86/include/asm/paravirt_types.h index 09c9e1dd81ce..b4a23eafa1b9 100644 --- a/arch/x86/include/asm/paravirt_types.h +++ b/arch/x86/include/asm/paravirt_types.h @@ -155,8 +155,14 @@ struct pv_cpu_ops { void (*cpuid)(unsigned int *eax, unsigned int *ebx, unsigned int *ecx, unsigned int *edx); - /* MSR operations. - err = 0/-EIO. wrmsr returns 0/-EIO. */ + /* Unsafe MSR operations. These will warn or panic on failure. */ + u64 (*read_msr)(unsigned int msr); + void (*write_msr)(unsigned int msr, unsigned low, unsigned high); + + /* + * Safe MSR operations. + * read sets err to 0 or -EIO. write returns 0 or -EIO. + */ u64 (*read_msr_safe)(unsigned int msr, int *err); int (*write_msr_safe)(unsigned int msr, unsigned low, unsigned high); |