x86, msr: Add rd/wrmsr interfaces with preset registers
native_{rdmsr,wrmsr}_safe_regs are two new interfaces which allow
presetting of a subset of eight x86 GPRs before executing the rd/wrmsr
instructions. This is needed at least on AMD K8 for accessing an erratum
workaround MSR.
Originally based on an idea by H. Peter Anvin.
Signed-off-by: Borislav Petkov <petkovbb@gmail.com>
LKML-Reference: <1251705011-18636-1-git-send-email-petkovbb@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c
index 70ec9b9..67594af 100644
--- a/arch/x86/kernel/paravirt.c
+++ b/arch/x86/kernel/paravirt.c
@@ -362,8 +362,10 @@
#endif
.wbinvd = native_wbinvd,
.read_msr = native_read_msr_safe,
+ .rdmsr_regs = native_rdmsr_safe_regs,
.read_msr_amd = native_read_msr_amd_safe,
.write_msr = native_write_msr_safe,
+ .wrmsr_regs = native_wrmsr_safe_regs,
.read_tsc = native_read_tsc,
.read_pmc = native_read_pmc,
.read_tscp = native_read_tscp,