aboutsummaryrefslogtreecommitdiff
path: root/hw/gusemu.h
diff options
context:
space:
mode:
authorAndre Przywara <andre.przywara@amd.com>2009-09-19 00:30:49 +0200
committerAurelien Jarno <aurelien@aurel32.net>2009-10-04 14:46:34 +0200
commit1b050077d2d72b15c73257c13e2e46932786f7e2 (patch)
treedc42c285ca15dc1901ef7f6ae268d583521300d5 /hw/gusemu.h
parentd9f4bb27dbff2e40ec2e36eb8017c9dedce77f30 (diff)
target-i386: add RDTSCP support
RDTSCP reads the time stamp counter and atomically also the content of a 32-bit MSR, which can be freely set by the OS. This allows CPU local data to be queried by userspace. Linux uses this to allow a fast implementation of the getcpu() syscall, which uses the vsyscall page to avoid a context switch. AMD CPUs since K8RevF and Intel CPUs since Nehalem support this instruction. RDTSCP is guarded by the RDTSCP CPUID bit (Fn8000_0001:EDX[27]). Signed-off-by: Andre Przywara <andre.przywara@amd.com> Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Diffstat (limited to 'hw/gusemu.h')
0 files changed, 0 insertions, 0 deletions