From e53dc1608f9528b2db5abd8c786d46cd93a24c4d Mon Sep 17 00:00:00 2001 From: Keir Fraser Date: Fri, 13 Aug 2010 08:31:49 +0100 Subject: [PATCH] svm: increment RIP over PAUSE instruction when emulating it Signed-off-by: Christoph Egger --- xen/arch/x86/hvm/svm/emulate.c | 4 +++- xen/arch/x86/hvm/svm/svm.c | 23 +++++++++++++++++------ xen/include/asm-x86/hvm/svm/emulate.h | 1 + 3 files changed, 21 insertions(+), 7 deletions(-) diff --git a/xen/arch/x86/hvm/svm/emulate.c b/xen/arch/x86/hvm/svm/emulate.c index 2c1693b878..2537dd2445 100644 --- a/xen/arch/x86/hvm/svm/emulate.c +++ b/xen/arch/x86/hvm/svm/emulate.c @@ -100,6 +100,7 @@ MAKE_INSTR(VMCALL, 3, 0x0f, 0x01, 0xd9); MAKE_INSTR(HLT, 1, 0xf4); MAKE_INSTR(INT3, 1, 0xcc); MAKE_INSTR(RDTSC, 2, 0x0f, 0x31); +MAKE_INSTR(PAUSE, 1, 0x90); static const u8 *opc_bytes[INSTR_MAX_COUNT] = { @@ -111,7 +112,8 @@ static const u8 *opc_bytes[INSTR_MAX_COUNT] = [INSTR_VMCALL] = OPCODE_VMCALL, [INSTR_HLT] = OPCODE_HLT, [INSTR_INT3] = OPCODE_INT3, - [INSTR_RDTSC] = OPCODE_RDTSC + [INSTR_RDTSC] = OPCODE_RDTSC, + [INSTR_PAUSE] = OPCODE_PAUSE, }; static int fetch(struct vcpu *v, u8 *buf, unsigned long addr, int len) diff --git a/xen/arch/x86/hvm/svm/svm.c b/xen/arch/x86/hvm/svm/svm.c index 1706c7fc94..7651012c40 100644 --- a/xen/arch/x86/hvm/svm/svm.c +++ b/xen/arch/x86/hvm/svm/svm.c @@ -1261,6 +1261,22 @@ static void svm_vmexit_do_rdtsc(struct cpu_user_regs *regs) hvm_rdtsc_intercept(regs); } +static void svm_vmexit_do_pause(struct cpu_user_regs *regs) +{ + unsigned int inst_len; + + if ( (inst_len = __get_instruction_length(current, INSTR_PAUSE)) == 0 ) + return; + __update_guest_eip(regs, inst_len); + + /* + * The guest is running a contended spinlock and we've detected it. + * Do something useful, like reschedule the guest + */ + perfc_incr(pauseloop_exits); + do_sched_op_compat(SCHEDOP_yield, 0); +} + static void svm_vmexit_ud_intercept(struct cpu_user_regs *regs) { struct hvm_emulate_ctxt ctxt; @@ -1655,12 +1671,7 @@ asmlinkage void svm_vmexit_handler(struct cpu_user_regs *regs) break; case VMEXIT_PAUSE: - /* - * The guest is running a contended spinlock and we've detected it. - * Do something useful, like reschedule the guest - */ - perfc_incr(pauseloop_exits); - do_sched_op_compat(SCHEDOP_yield, 0); + svm_vmexit_do_pause(regs); break; default: diff --git a/xen/include/asm-x86/hvm/svm/emulate.h b/xen/include/asm-x86/hvm/svm/emulate.h index 7f7a67f1db..b06f98e06f 100644 --- a/xen/include/asm-x86/hvm/svm/emulate.h +++ b/xen/include/asm-x86/hvm/svm/emulate.h @@ -31,6 +31,7 @@ enum instruction_index { INSTR_HLT, INSTR_INT3, INSTR_RDTSC, + INSTR_PAUSE, INSTR_MAX_COUNT /* Must be last - Number of instructions supported */ }; -- 2.30.2