# HG changeset patch
# User Keir Fraser <keir.fraser@xxxxxxxxxx>
# Date 1196115621 0
# Node ID f9a43c6b5be13ccad25e80cdcc76c4351f2b7625
# Parent 4d6f92fa1014101fff9f01bb3998ca57b139c9b5
vmx realmode: When returning to protected mode we have to massage the
segment state to pass VMENTER's stringent 'sanity checks'.
Signed-off-by: Keir Fraser <keir.fraser@xxxxxxxxxx>
---
xen/arch/x86/hvm/vmx/realmode.c | 29 ++++++++++++++++++++++-------
1 files changed, 22 insertions(+), 7 deletions(-)
diff -r 4d6f92fa1014 -r f9a43c6b5be1 xen/arch/x86/hvm/vmx/realmode.c
--- a/xen/arch/x86/hvm/vmx/realmode.c Mon Nov 26 17:55:23 2007 +0000
+++ b/xen/arch/x86/hvm/vmx/realmode.c Mon Nov 26 22:20:21 2007 +0000
@@ -524,7 +524,8 @@ void vmx_realmode(struct cpu_user_regs *
if ( rc == X86EMUL_UNHANDLEABLE )
{
gdprintk(XENLOG_DEBUG,
- "RM %04x:%08lx: %02x %02x %02x %02x %02x %02x\n",
+ "Real-mode emulation failed @ %04x:%08lx: "
+ "%02x %02x %02x %02x %02x %02x\n",
rm_ctxt.seg_reg[x86_seg_cs].sel, rm_ctxt.insn_buf_eip,
rm_ctxt.insn_buf[0], rm_ctxt.insn_buf[1],
rm_ctxt.insn_buf[2], rm_ctxt.insn_buf[3],
@@ -534,6 +535,26 @@ void vmx_realmode(struct cpu_user_regs *
}
}
+ /*
+ * Cannot enter protected mode with bogus selector RPLs and DPLs. Hence we
+ * fix up as best we can, even though this deviates from native execution
+ */
+ if ( curr->arch.hvm_vcpu.guest_cr[0] & X86_CR0_PE )
+ {
+ /* CS.RPL == SS.RPL == SS.DPL == 0. */
+ rm_ctxt.seg_reg[x86_seg_cs].sel &= ~3;
+ rm_ctxt.seg_reg[x86_seg_ss].sel &= ~3;
+ /* DS,ES,FS,GS: The most uninvasive trick is to set DPL == RPL. */
+ rm_ctxt.seg_reg[x86_seg_ds].attr.fields.dpl =
+ rm_ctxt.seg_reg[x86_seg_ds].sel & 3;
+ rm_ctxt.seg_reg[x86_seg_es].attr.fields.dpl =
+ rm_ctxt.seg_reg[x86_seg_es].sel & 3;
+ rm_ctxt.seg_reg[x86_seg_fs].attr.fields.dpl =
+ rm_ctxt.seg_reg[x86_seg_fs].sel & 3;
+ rm_ctxt.seg_reg[x86_seg_gs].attr.fields.dpl =
+ rm_ctxt.seg_reg[x86_seg_gs].sel & 3;
+ }
+
for ( i = 0; i < 10; i++ )
hvm_set_segment_register(curr, i, &rm_ctxt.seg_reg[i]);
}
@@ -546,12 +567,6 @@ int vmx_realmode_io_complete(void)
if ( !curr->arch.hvm_vmx.real_mode_io_in_progress )
return 0;
-#if 0
- gdprintk(XENLOG_DEBUG, "RM I/O %d %c bytes=%d addr=%lx data=%lx\n",
- p->type, p->dir ? 'R' : 'W',
- (int)p->size, (long)p->addr, (long)p->data);
-#endif
-
curr->arch.hvm_vmx.real_mode_io_in_progress = 0;
if ( p->dir == IOREQ_READ )
{
_______________________________________________
Xen-changelog mailing list
Xen-changelog@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-changelog
|
Home