RE: [RFC Part1 PATCH v3 13/17] x86/io: Unroll string I/O when SEV is active
From: David Laight <hidden>
Date: 2017-07-25 09:51:36
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From: Brijesh Singh
quoted hunk ↗ jump to hunk
Sent: 24 July 2017 20:08 From: Tom Lendacky <thomas.lendacky@amd.com> =20 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. =20 Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Brijesh Singh <redacted> --- arch/x86/include/asm/io.h | 26 ++++++++++++++++++++++---- 1 file changed, 22 insertions(+), 4 deletions(-) =20diff --git a/arch/x86/include/asm/io.h b/arch/x86/include/asm/io.h index e080a39..2f3c002 100644 --- a/arch/x86/include/asm/io.h +++ b/arch/x86/include/asm/io.h@@ -327,14 +327,32 @@ static inline unsigned type in##bwl##_p(int port) =
\
\ static inline void outs##bwl(int port, const void *addr, unsigned long c=
ount) \
{Is it even worth leaving these as inline functions? Given the speed of IO cycles it is unlikely that the cost of calling a real function will be significant. The code bloat reduction will be significant. David