Commit 8539d3f0 authored by Sean Christopherson's avatar Sean Christopherson Committed by Borislav Petkov
Browse files

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

  6a3ea3e6 ("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: default avatarSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20201027214532.1792-1-sean.j.christopherson@intel.com
parent ab09b58e

arch/x86/include/asm/inst.h

+0 −15
Original line number Diff line number Diff line
@@ -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