The following commit has been merged into the x86/cleanups branch of tip:

Commit-ID:     8539d3f06710a9e91b9968fa736549d7c6b44206
Gitweb:        
https://git.kernel.org/tip/8539d3f06710a9e91b9968fa736549d7c6b44206
Author:        Sean Christopherson <[email protected]>
AuthorDate:    Tue, 27 Oct 2020 14:45:32 -07:00
Committer:     Borislav Petkov <[email protected]>
CommitterDate: Thu, 26 Nov 2020 12:58:56 +01:00

x86/asm: Drop unused RDPID macro

Drop the GAS-compatible RDPID macro. RDPID is unsafe in the kernel
because KVM loads guest's TSC_AUX on VM-entry and may not restore the
host's value until the CPU returns to userspace.

See

  6a3ea3e68b8a ("x86/entry/64: Do not use RDPID in paranoid entry to accomodate 
KVM")

for details.

It can always be resurrected from git history, if needed.

 [ bp: Massage commit message. ]

Signed-off-by: Sean Christopherson <[email protected]>
Signed-off-by: Borislav Petkov <[email protected]>
Link: 
https://lkml.kernel.org/r/[email protected]
---
 arch/x86/include/asm/inst.h | 15 ---------------
 1 file changed, 15 deletions(-)

diff --git a/arch/x86/include/asm/inst.h b/arch/x86/include/asm/inst.h
index bd7f024..438ccd4 100644
--- a/arch/x86/include/asm/inst.h
+++ b/arch/x86/include/asm/inst.h
@@ -143,21 +143,6 @@
        .macro MODRM mod opd1 opd2
        .byte \mod | (\opd1 & 7) | ((\opd2 & 7) << 3)
        .endm
-
-.macro RDPID opd
-       REG_TYPE rdpid_opd_type \opd
-       .if rdpid_opd_type == REG_TYPE_R64
-       R64_NUM rdpid_opd \opd
-       .else
-       R32_NUM rdpid_opd \opd
-       .endif
-       .byte 0xf3
-       .if rdpid_opd > 7
-       PFX_REX rdpid_opd 0
-       .endif
-       .byte 0x0f, 0xc7
-       MODRM 0xc0 rdpid_opd 0x7
-.endm
 #endif
 
 #endif

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