# HG changeset patch
# User Keir Fraser <keir.fraser@xxxxxxxxxx>
# Date 1219756217 -3600
# Node ID 493a0a87919e4403d88dc716254fbdf646afa2f1
# Parent 62b904dcf88c4549620741fcd16e9b33b53ea289
x86 hvm: Emulate RAM-to-RAM REP MOVS copies efficiently.
Signed-off-by: Keir Fraser <keir.fraser@xxxxxxxxxx>
---
xen/arch/x86/hvm/emulate.c | 29 ++++++++++++++++++++++-------
1 files changed, 22 insertions(+), 7 deletions(-)
diff -r 62b904dcf88c -r 493a0a87919e xen/arch/x86/hvm/emulate.c
--- a/xen/arch/x86/hvm/emulate.c Tue Aug 26 13:00:43 2008 +0100
+++ b/xen/arch/x86/hvm/emulate.c Tue Aug 26 14:10:17 2008 +0100
@@ -575,7 +575,8 @@ static int hvmemul_rep_movs(
paddr_t sgpa, dgpa;
uint32_t pfec = PFEC_page_present;
p2m_type_t p2mt;
- int rc;
+ int rc, df = !!(ctxt->regs->eflags & X86_EFLAGS_DF);
+ char *buf;
rc = hvmemul_virtual_to_linear(
src_seg, src_offset, bytes_per_rep, reps, hvm_access_read,
@@ -606,15 +607,29 @@ static int hvmemul_rep_movs(
(void)gfn_to_mfn_current(sgpa >> PAGE_SHIFT, &p2mt);
if ( !p2m_is_ram(p2mt) )
return hvmemul_do_mmio(
- sgpa, reps, bytes_per_rep, dgpa, IOREQ_READ,
- !!(ctxt->regs->eflags & X86_EFLAGS_DF), NULL);
+ sgpa, reps, bytes_per_rep, dgpa, IOREQ_READ, df, NULL);
(void)gfn_to_mfn_current(dgpa >> PAGE_SHIFT, &p2mt);
- if ( p2m_is_ram(p2mt) )
+ if ( !p2m_is_ram(p2mt) )
+ return hvmemul_do_mmio(
+ dgpa, reps, bytes_per_rep, sgpa, IOREQ_WRITE, df, NULL);
+
+ if ( df )
+ {
+ sgpa -= (*reps - 1) * bytes_per_rep;
+ dgpa -= (*reps - 1) * bytes_per_rep;
+ }
+
+ buf = xmalloc_bytes(*reps * bytes_per_rep);
+ if ( buf == NULL )
return X86EMUL_UNHANDLEABLE;
- return hvmemul_do_mmio(
- dgpa, reps, bytes_per_rep, sgpa, IOREQ_WRITE,
- !!(ctxt->regs->eflags & X86_EFLAGS_DF), NULL);
+
+ hvm_copy_from_guest_phys(buf, sgpa, *reps * bytes_per_rep);
+ hvm_copy_to_guest_phys(dgpa, buf, *reps * bytes_per_rep);
+
+ xfree(buf);
+
+ return X86EMUL_OKAY;
}
static int hvmemul_read_segment(
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