xen/16929-hvm-guest-crash-fix.patch

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# HG changeset patch
# User Keir Fraser <keir.fraser@citrix.com>
# Date 1201607262 0
# Node ID 128f7bc0a277375571b4817fc65bfcd14e00a7ec
# Parent 7aa2149a3b0e94eb01b39ae8cf4a41bc225be94e
x86: Fix HVM hypercall preemption causing guest crash.
Signed-off-by: Yu Zhao <yu.zhao@intel.com>
Index: xen-3.2-testing/xen/arch/x86/domain.c
===================================================================
--- xen-3.2-testing.orig/xen/arch/x86/domain.c
+++ xen-3.2-testing/xen/arch/x86/domain.c
@@ -1507,7 +1507,12 @@ unsigned long hypercall_create_continuat
{
regs = guest_cpu_user_regs();
regs->eax = op;
- regs->eip -= 2; /* re-execute 'syscall' / 'int 0x82' */
+ /*
+ * For PV guest, we update EIP to re-execute 'syscall' / 'int 0x82';
+ * HVM does not need this since 'vmcall' / 'vmmcall' is fault-like.
+ */
+ if ( !is_hvm_vcpu(current) )
+ regs->eip -= 2; /* re-execute 'syscall' / 'int 0x82' */
#ifdef __x86_64__
if ( !is_hvm_vcpu(current) ?