diff options
| author | Tom Lendacky <thomas.lendacky@amd.com> | 2017-10-20 17:30:55 +0300 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2017-11-07 17:35:59 +0300 |
| commit | 606b21d4a6498c23632a4693c81b7b24feedd038 (patch) | |
| tree | 6d5275209c0febbce0963bd871e5103aba01f921 /arch/x86/include/asm/io.h | |
| parent | 1958b5fc401067662ec11a6fcbe0daa26c813603 (diff) | |
| download | linux-606b21d4a6498c23632a4693c81b7b24feedd038.tar.xz | |
x86/io: Unroll string I/O when SEV is active
Secure Encrypted Virtualization (SEV) does not support string I/O, so
unroll the string I/O operation into a loop operating on one element at
a time.
[ tglx: Gave the static key a real name instead of the obscure __sev ]
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Tested-by: Borislav Petkov <bp@suse.de>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: kvm@vger.kernel.org
Cc: David Laight <David.Laight@ACULAB.COM>
Cc: Borislav Petkov <bp@alien8.de>
Link: https://lkml.kernel.org/r/20171020143059.3291-14-brijesh.singh@amd.com
Diffstat (limited to 'arch/x86/include/asm/io.h')
| -rw-r--r-- | arch/x86/include/asm/io.h | 43 |
1 files changed, 39 insertions, 4 deletions
diff --git a/arch/x86/include/asm/io.h b/arch/x86/include/asm/io.h index 11398d55aefa..93ae8aee1780 100644 --- a/arch/x86/include/asm/io.h +++ b/arch/x86/include/asm/io.h @@ -266,6 +266,21 @@ static inline void slow_down_io(void) #endif +#ifdef CONFIG_AMD_MEM_ENCRYPT +#include <linux/jump_label.h> + +extern struct static_key_false sev_enable_key; +static inline bool sev_key_active(void) +{ + return static_branch_unlikely(&sev_enable_key); +} + +#else /* !CONFIG_AMD_MEM_ENCRYPT */ + +static inline bool sev_key_active(void) { return false; } + +#endif /* CONFIG_AMD_MEM_ENCRYPT */ + #define BUILDIO(bwl, bw, type) \ static inline void out##bwl(unsigned type value, int port) \ { \ @@ -296,14 +311,34 @@ static inline unsigned type in##bwl##_p(int port) \ \ static inline void outs##bwl(int port, const void *addr, unsigned long count) \ { \ - asm volatile("rep; outs" #bwl \ - : "+S"(addr), "+c"(count) : "d"(port) : "memory"); \ + if (sev_key_active()) { \ + unsigned type *value = (unsigned type *)addr; \ + while (count) { \ + out##bwl(*value, port); \ + value++; \ + count--; \ + } \ + } else { \ + asm volatile("rep; outs" #bwl \ + : "+S"(addr), "+c"(count) \ + : "d"(port) : "memory"); \ + } \ } \ \ static inline void ins##bwl(int port, void *addr, unsigned long count) \ { \ - asm volatile("rep; ins" #bwl \ - : "+D"(addr), "+c"(count) : "d"(port) : "memory"); \ + if (sev_key_active()) { \ + unsigned type *value = (unsigned type *)addr; \ + while (count) { \ + *value = in##bwl(port); \ + value++; \ + count--; \ + } \ + } else { \ + asm volatile("rep; ins" #bwl \ + : "+D"(addr), "+c"(count) \ + : "d"(port) : "memory"); \ + } \ } BUILDIO(b, b, char) |