diff options
-rw-r--r-- | xen/arch/x86/hvm/emulate.c | 57 | ||||
-rw-r--r-- | xen/include/asm-x86/hvm/vcpu.h | 3 |
2 files changed, 46 insertions, 14 deletions
diff --git a/xen/arch/x86/hvm/emulate.c b/xen/arch/x86/hvm/emulate.c index 6cb6678175..f39c17358e 100644 --- a/xen/arch/x86/hvm/emulate.c +++ b/xen/arch/x86/hvm/emulate.c @@ -569,9 +569,19 @@ static int hvmemul_insn_fetch( /* Fall back if requested bytes are not in the prefetch cache. */ if ( unlikely((insn_off + bytes) > hvmemul_ctxt->insn_buf_bytes) ) - return __hvmemul_read( - seg, offset, p_data, bytes, - hvm_access_insn_fetch, hvmemul_ctxt); + { + int rc = __hvmemul_read(seg, offset, p_data, bytes, + hvm_access_insn_fetch, hvmemul_ctxt); + + if ( rc == X86EMUL_OKAY ) + { + ASSERT(insn_off + bytes <= sizeof(hvmemul_ctxt->insn_buf)); + memcpy(&hvmemul_ctxt->insn_buf[insn_off], p_data, bytes); + hvmemul_ctxt->insn_buf_bytes = insn_off + bytes; + } + + return rc; + } /* Hit the cache. Simple memcpy. */ memcpy(p_data, &hvmemul_ctxt->insn_buf[insn_off], bytes); @@ -1148,17 +1158,27 @@ int hvm_emulate_one( pfec |= PFEC_user_mode; 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), - hvm_access_insn_fetch, hvmemul_ctxt->ctxt.addr_size, &addr) && - !hvm_fetch_from_guest_virt_nofault( - hvmemul_ctxt->insn_buf, addr, - sizeof(hvmemul_ctxt->insn_buf), pfec)) - ? sizeof(hvmemul_ctxt->insn_buf) : 0; + if ( !vio->mmio_insn_bytes ) + { + 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), + hvm_access_insn_fetch, + hvmemul_ctxt->ctxt.addr_size, + &addr) && + hvm_fetch_from_guest_virt_nofault(hvmemul_ctxt->insn_buf, addr, + sizeof(hvmemul_ctxt->insn_buf), + pfec) == HVMCOPY_okay) ? + sizeof(hvmemul_ctxt->insn_buf) : 0; + } + else + { + hvmemul_ctxt->insn_buf_bytes = vio->mmio_insn_bytes; + memcpy(hvmemul_ctxt->insn_buf, vio->mmio_insn, vio->mmio_insn_bytes); + } hvmemul_ctxt->exn_pending = 0; vio->mmio_retrying = vio->mmio_retry; @@ -1169,7 +1189,16 @@ int hvm_emulate_one( if ( rc == X86EMUL_OKAY && vio->mmio_retry ) rc = X86EMUL_RETRY; if ( rc != X86EMUL_RETRY ) + { vio->mmio_large_read_bytes = vio->mmio_large_write_bytes = 0; + vio->mmio_insn_bytes = 0; + } + else + { + BUILD_BUG_ON(sizeof(vio->mmio_insn) < sizeof(hvmemul_ctxt->insn_buf)); + vio->mmio_insn_bytes = hvmemul_ctxt->insn_buf_bytes; + memcpy(vio->mmio_insn, hvmemul_ctxt->insn_buf, vio->mmio_insn_bytes); + } if ( rc != X86EMUL_OKAY ) return rc; diff --git a/xen/include/asm-x86/hvm/vcpu.h b/xen/include/asm-x86/hvm/vcpu.h index 1abb364b07..8fa5452ab1 100644 --- a/xen/include/asm-x86/hvm/vcpu.h +++ b/xen/include/asm-x86/hvm/vcpu.h @@ -66,6 +66,9 @@ struct hvm_vcpu_io { /* We may write up to m256 as a number of device-model transactions. */ unsigned int mmio_large_write_bytes; paddr_t mmio_large_write_pa; + /* For retries we shouldn't re-fetch the instruction. */ + unsigned int mmio_insn_bytes; + unsigned char mmio_insn[16]; /* * For string instruction emulation we need to be able to signal a * necessary retry through other than function return codes. |