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| author | Keir Fraser <keir@xen.org> | 2011-04-18 13:36:10 +0100 |
|---|---|---|
| committer | Keir Fraser <keir@xen.org> | 2011-04-18 13:36:10 +0100 |
| commit | deb245252e80db10906d42dd831d1927ded9c294 (patch) | |
| tree | cbd4612bb15275b855f367222aad04519c9a2faa /xen/arch/x86/hvm/emulate.c | |
| parent | 88f1c41bd86e47a2b18e5cfda4df305287ae30e9 (diff) | |
| download | xen-deb245252e80db10906d42dd831d1927ded9c294.tar.gz xen-deb245252e80db10906d42dd831d1927ded9c294.tar.bz2 xen-deb245252e80db10906d42dd831d1927ded9c294.zip | |
svm: implement instruction fetch part of DecodeAssist (on #PF/#NPF)
Newer SVM implementations (Bulldozer) copy up to 15 bytes from the
instruction stream into the VMCB when a #PF or #NPF exception is
intercepted. This patch makes use of this information if available.
This saves us from a) traversing the guest's page tables, b) mapping
the guest's memory and c) copy the instructions from there into the
hypervisor's address space.
This speeds up #NPF intercepts quite a lot and avoids cache and TLB
trashing.
Signed-off-by: Andre Przywara <andre.przywara@amd.com>
Signed-off-by: Keir Fraser <keir@xen.org>
Diffstat (limited to 'xen/arch/x86/hvm/emulate.c')
| -rw-r--r-- | xen/arch/x86/hvm/emulate.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/xen/arch/x86/hvm/emulate.c b/xen/arch/x86/hvm/emulate.c index af903c9b72..1230de6031 100644 --- a/xen/arch/x86/hvm/emulate.c +++ b/xen/arch/x86/hvm/emulate.c @@ -996,6 +996,8 @@ int hvm_emulate_one( hvmemul_ctxt->insn_buf_eip = regs->eip; hvmemul_ctxt->insn_buf_bytes = + hvm_get_insn_bytes(curr, hvmemul_ctxt->insn_buf) + ? : (hvm_virtual_to_linear_addr( x86_seg_cs, &hvmemul_ctxt->seg_reg[x86_seg_cs], regs->eip, sizeof(hvmemul_ctxt->insn_buf), |