From 6b4600b1425ef8006efcd2cdb4c4c986309264f6 Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Tue, 4 Dec 2018 14:02:46 +0100 Subject: [PATCH] x86emul: skip VIF processing in VME mode for 16-bit POPF at IOPL 3 At IOPL 3 CR4.VME is irrelevant. Reported-by: Andrew Cooper Signed-off-by: Jan Beulich Reviewed-by: Andrew Cooper --- xen/arch/x86/x86_emulate/x86_emulate.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/xen/arch/x86/x86_emulate/x86_emulate.c b/xen/arch/x86/x86_emulate/x86_emulate.c index 0ae433538e..5313145b63 100644 --- a/xen/arch/x86/x86_emulate/x86_emulate.c +++ b/xen/arch/x86/x86_emulate/x86_emulate.c @@ -4223,7 +4223,8 @@ x86_emulate( if ( op_bytes == 2 ) { dst.val = (uint16_t)dst.val | (_regs.eflags & 0xffff0000u); - if ( cr4 & X86_CR4_VME ) + if ( (cr4 & X86_CR4_VME) && + MASK_EXTR(_regs.eflags, X86_EFLAGS_IOPL) != 3 ) { if ( dst.val & X86_EFLAGS_IF ) { -- 2.30.2