diff options
| author | Tom Lendacky <thomas.lendacky@amd.com> | 2017-10-20 09:30:55 -0500 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2017-11-07 15:35:59 +0100 |
| commit | 606b21d4a6498c23632a4693c81b7b24feedd038 (patch) | |
| tree | 6d5275209c0febbce0963bd871e5103aba01f921 /arch/x86/mm | |
| parent | 1958b5fc401067662ec11a6fcbe0daa26c813603 (diff) | |
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/mm')
| -rw-r--r-- | arch/x86/mm/mem_encrypt.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c index fd9c7bb51664..d29b7831a053 100644 --- a/arch/x86/mm/mem_encrypt.c +++ b/arch/x86/mm/mem_encrypt.c @@ -41,6 +41,8 @@ static char sme_cmdline_off[] __initdata = "off"; */ u64 sme_me_mask __section(.data) = 0; EXPORT_SYMBOL_GPL(sme_me_mask); +DEFINE_STATIC_KEY_FALSE(sev_enable_key); +EXPORT_SYMBOL_GPL(sev_enable_key); static bool sev_enabled __section(.data); @@ -313,6 +315,12 @@ void __init mem_encrypt_init(void) if (sev_active()) dma_ops = &sev_dma_ops; + /* + * With SEV, we need to unroll the rep string I/O instructions. + */ + if (sev_active()) + static_branch_enable(&sev_enable_key); + pr_info("AMD %s active\n", sev_active() ? "Secure Encrypted Virtualization (SEV)" : "Secure Memory Encryption (SME)"); |