From c378ff8983cd69786c35117e49640f027e581bca Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Roger=20Pau=20Monn=C3=A9?= Date: Fri, 26 Jan 2024 15:54:18 +0100 Subject: [PATCH] x86/entry: fix jump into restore_all_guest without %rbx correctly set MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit e047b8d0fa05 went too far when limiting obtaining the vCPU pointer. While the code in ist_dispatch_done does indeed only need the vCPU pointer when PV32 is enabled, the !PV32 path will end up jumping into restore_all_guest which does require rbx == vCPU pointer. Fix by moving the fetching of the vCPU pointer to be done outside of the PV32 code block. Fixes: e047b8d0fa05 ('x86/entry: replace two GET_CURRENT() uses') Reported-by: Edwin Torok Signed-off-by: Roger Pau Monné Reviewed-by: Andrew Cooper --- xen/arch/x86/x86_64/entry.S | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/xen/arch/x86/x86_64/entry.S b/xen/arch/x86/x86_64/entry.S index 44f25def86..ecdd6e5b47 100644 --- a/xen/arch/x86/x86_64/entry.S +++ b/xen/arch/x86/x86_64/entry.S @@ -1139,8 +1139,9 @@ FUNC(handle_ist_exception) movl $EVENT_CHECK_VECTOR,%edi call send_IPI_self 1: -#ifdef CONFIG_PV32 + /* For restore_all_guest. */ mov STACK_CPUINFO_FIELD(current_vcpu)(%r14), %rbx +#ifdef CONFIG_PV32 movq VCPU_domain(%rbx),%rax cmpb $0,DOMAIN_is_32bit_pv(%rax) je restore_all_guest