From d6d3c05250536f81aa988207fc83c4a3a7cccb6a Mon Sep 17 00:00:00 2001 From: Keir Fraser Date: Fri, 23 Oct 2009 10:13:52 +0100 Subject: [PATCH] x86 ept: ignore guest writes to read only memory regions or memory holes in EPT. This patch prevents domain crash when running memtest86 with EPT. Signed-off-by: Xin Li --- xen/arch/x86/hvm/vmx/vmx.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/xen/arch/x86/hvm/vmx/vmx.c b/xen/arch/x86/hvm/vmx/vmx.c index e187677dd3..d85b3d877b 100644 --- a/xen/arch/x86/hvm/vmx/vmx.c +++ b/xen/arch/x86/hvm/vmx/vmx.c @@ -2184,6 +2184,17 @@ static void ept_handle_violation(unsigned long qualification, paddr_t gpa) return; } + /* Ignore writes to: + * 1. read only memory regions; + * 2. memory holes. */ + if ( (qualification & EPT_WRITE_VIOLATION) + && (((gla_validity == EPT_GLA_VALIDITY_MATCH) && (t == p2m_ram_ro)) + || (mfn_x(mfn) == INVALID_MFN)) ) { + int inst_len = __get_instruction_length(); + __update_guest_eip(inst_len); + return; + } + /* Everything else is an error. */ gla = __vmread(GUEST_LINEAR_ADDRESS); gdprintk(XENLOG_ERR, "EPT violation %#lx (%c%c%c/%c%c%c), " -- 2.30.2