From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49244) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1f0OJ0-0007BV-Qw for qemu-devel@nongnu.org; Mon, 26 Mar 2018 05:20:44 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1f0OIx-0006P1-LF for qemu-devel@nongnu.org; Mon, 26 Mar 2018 05:20:42 -0400 From: David Hildenbrand Date: Mon, 26 Mar 2018 11:20:36 +0200 Message-Id: <20180326092036.12780-1-david@redhat.com> Subject: [Qemu-devel] [PATCH RFC] s390x/kvm: call cpu_synchronize_state() on every kvm_arch_handle_exit() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-s390x@nongnu.org Cc: qemu-devel@nongnu.org, Richard Henderson , Alexander Graf , Cornelia Huck , Christian Borntraeger , Thomas Huth , David Hildenbrand Manually having to use cpu_synchronize_state() is error prone. I don't think that the performance impact is that huge if we simply synchronize the state on every kvm_arch_handle_exit() call. This makes the code easier to maintain. We now also call it (although not neded) for - KVM_EXIT_S390_RESET -> s390_reipl_request() - KVM_EXIT_DEBUG -> kvm_arch_handle_debug_exit() - unmanagable/unimplemented intercepts - ICPT_WAITPSW -> s390_handle_wait() -> cpu gets halted - ICPT_CPU_STOP -> do_stop_interrupt() -> cpu gets halted - Scenarios where we inject an operation exception - handle_sigp() on the source CPU - handle_stsi() I don't think any of these are performance critical. Especially as we have all information directly contained in kvm_run, there are no additional IOCTLs to issue on modern kernels. Remaining places (for s390x) are in - target/s390x/sigp.c, on the target CPU - target/s390x/cpu.c:s390_cpu_get_crash_info() Signed-off-by: David Hildenbrand --- hw/s390x/s390-pci-inst.c | 8 -------- target/s390x/kvm.c | 20 ++------------------ 2 files changed, 2 insertions(+), 26 deletions(-) diff --git a/hw/s390x/s390-pci-inst.c b/hw/s390x/s390-pci-inst.c index 3fcc330fe3..02a815fd31 100644 --- a/hw/s390x/s390-pci-inst.c +++ b/hw/s390x/s390-pci-inst.c @@ -155,8 +155,6 @@ int clp_service_call(S390CPU *cpu, uint8_t r2, uintptr_t ra) S390pciState *s = s390_get_phb(); int i; - cpu_synchronize_state(CPU(cpu)); - if (env->psw.mask & PSW_MASK_PSTATE) { s390_program_interrupt(env, PGM_PRIVILEGED, 4, ra); return 0; @@ -389,8 +387,6 @@ int pcilg_service_call(S390CPU *cpu, uint8_t r1, uint8_t r2, uintptr_t ra) uint32_t fh; uint8_t pcias; - cpu_synchronize_state(CPU(cpu)); - if (env->psw.mask & PSW_MASK_PSTATE) { s390_program_interrupt(env, PGM_PRIVILEGED, 4, ra); return 0; @@ -487,8 +483,6 @@ int pcistg_service_call(S390CPU *cpu, uint8_t r1, uint8_t r2, uintptr_t ra) uint32_t fh; uint8_t pcias; - cpu_synchronize_state(CPU(cpu)); - if (env->psw.mask & PSW_MASK_PSTATE) { s390_program_interrupt(env, PGM_PRIVILEGED, 4, ra); return 0; @@ -620,8 +614,6 @@ int rpcit_service_call(S390CPU *cpu, uint8_t r1, uint8_t r2, uintptr_t ra) S390IOTLBEntry entry; hwaddr start, end; - cpu_synchronize_state(CPU(cpu)); - if (env->psw.mask & PSW_MASK_PSTATE) { s390_program_interrupt(env, PGM_PRIVILEGED, 4, ra); return 0; diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c index f570896dc1..7de861ab34 100644 --- a/target/s390x/kvm.c +++ b/target/s390x/kvm.c @@ -1081,7 +1081,6 @@ static int kvm_sclp_service_call(S390CPU *cpu, struct kvm_run *run, uint32_t code; int r = 0; - cpu_synchronize_state(CPU(cpu)); sccb = env->regs[ipbh0 & 0xf]; code = env->regs[(ipbh0 & 0xf0) >> 4]; @@ -1101,8 +1100,6 @@ static int handle_b2(S390CPU *cpu, struct kvm_run *run, uint8_t ipa1) int rc = 0; uint16_t ipbh0 = (run->s390_sieic.ipb & 0xffff0000) >> 16; - cpu_synchronize_state(CPU(cpu)); - switch (ipa1) { case PRIV_B2_XSCH: ioinst_handle_xsch(cpu, env->regs[1], RA_IGNORED); @@ -1248,7 +1245,6 @@ static int kvm_stpcifc_service_call(S390CPU *cpu, struct kvm_run *run) uint8_t ar; if (s390_has_feat(S390_FEAT_ZPCI)) { - cpu_synchronize_state(CPU(cpu)); fiba = get_base_disp_rxy(cpu, run, &ar); return stpcifc_service_call(cpu, r1, fiba, ar, RA_IGNORED); @@ -1266,7 +1262,6 @@ static int kvm_sic_service_call(S390CPU *cpu, struct kvm_run *run) uint16_t mode; int r; - cpu_synchronize_state(CPU(cpu)); mode = env->regs[r1] & 0xffff; isc = (env->regs[r3] >> 27) & 0x7; r = css_do_sic(env, isc, mode); @@ -1297,7 +1292,6 @@ static int kvm_pcistb_service_call(S390CPU *cpu, struct kvm_run *run) uint8_t ar; if (s390_has_feat(S390_FEAT_ZPCI)) { - cpu_synchronize_state(CPU(cpu)); gaddr = get_base_disp_rsy(cpu, run, &ar); return pcistb_service_call(cpu, r1, r3, gaddr, ar, RA_IGNORED); @@ -1313,7 +1307,6 @@ static int kvm_mpcifc_service_call(S390CPU *cpu, struct kvm_run *run) uint8_t ar; if (s390_has_feat(S390_FEAT_ZPCI)) { - cpu_synchronize_state(CPU(cpu)); fiba = get_base_disp_rxy(cpu, run, &ar); return mpcifc_service_call(cpu, r1, fiba, ar, RA_IGNORED); @@ -1401,7 +1394,6 @@ static int handle_hypercall(S390CPU *cpu, struct kvm_run *run) CPUS390XState *env = &cpu->env; int ret; - cpu_synchronize_state(CPU(cpu)); ret = s390_virtio_hypercall(env); if (ret == -EINVAL) { kvm_s390_program_interrupt(cpu, PGM_SPECIFICATION); @@ -1416,7 +1408,6 @@ static void kvm_handle_diag_288(S390CPU *cpu, struct kvm_run *run) uint64_t r1, r3; int rc; - cpu_synchronize_state(CPU(cpu)); r1 = (run->s390_sieic.ipa & 0x00f0) >> 4; r3 = run->s390_sieic.ipa & 0x000f; rc = handle_diag_288(&cpu->env, r1, r3); @@ -1429,7 +1420,6 @@ static void kvm_handle_diag_308(S390CPU *cpu, struct kvm_run *run) { uint64_t r1, r3; - cpu_synchronize_state(CPU(cpu)); r1 = (run->s390_sieic.ipa & 0x00f0) >> 4; r3 = run->s390_sieic.ipa & 0x000f; handle_diag_308(&cpu->env, r1, r3, RA_IGNORED); @@ -1440,8 +1430,6 @@ static int handle_sw_breakpoint(S390CPU *cpu, struct kvm_run *run) CPUS390XState *env = &cpu->env; unsigned long pc; - cpu_synchronize_state(CPU(cpu)); - pc = env->psw.addr - sw_bp_ilen; if (kvm_find_sw_breakpoint(CPU(cpu), pc)) { env->psw.addr = pc; @@ -1493,8 +1481,6 @@ static int kvm_s390_handle_sigp(S390CPU *cpu, uint8_t ipa1, uint32_t ipb) int ret; uint8_t order; - cpu_synchronize_state(CPU(cpu)); - /* get order code */ order = decode_basedisp_rs(env, ipb, NULL) & SIGP_ORDER_MASK; @@ -1556,7 +1542,6 @@ static int handle_oper_loop(S390CPU *cpu, struct kvm_run *run) CPUState *cs = CPU(cpu); PSW oldpsw, newpsw; - cpu_synchronize_state(cs); newpsw.mask = ldq_phys(cs->as, cpu->env.psa + offsetof(LowCore, program_new_psw)); newpsw.addr = ldq_phys(cs->as, cpu->env.psa + @@ -1609,7 +1594,6 @@ static int handle_intercept(S390CPU *cpu) break; case ICPT_WAITPSW: /* disabled wait, since enabled wait is handled in kernel */ - cpu_synchronize_state(cs); s390_handle_wait(cpu); r = EXCP_HALTED; break; @@ -1651,8 +1635,6 @@ static int handle_tsch(S390CPU *cpu) struct kvm_run *run = cs->kvm_run; int ret; - cpu_synchronize_state(cs); - ret = ioinst_handle_tsch(cpu, cpu->env.regs[1], run->s390_tsch.ipb, RA_IGNORED); if (ret < 0) { @@ -1778,6 +1760,8 @@ int kvm_arch_handle_exit(CPUState *cs, struct kvm_run *run) qemu_mutex_lock_iothread(); + cpu_synchronize_state(CPU(cpu)); + switch (run->exit_reason) { case KVM_EXIT_S390_SIEIC: ret = handle_intercept(cpu); -- 2.14.3