From 62a2744ca09a0b44b8406ea0c430c4c67a2c3231 Mon Sep 17 00:00:00 2001 From: Sheng Yang Date: Tue, 26 Jan 2010 19:21:16 +0800 Subject: [PATCH 1/6] kvm: Flush coalesced MMIO buffer periodly The default action of coalesced MMIO is, cache the writing in buffer, until: 1. The buffer is full. 2. Or the exit to QEmu due to other reasons. But this would result in a very late writing in some condition. 1. The each time write to MMIO content is small. 2. The writing interval is big. 3. No need for input or accessing other devices frequently. This issue was observed in a experimental embbed system. The test image simply print "test" every 1 seconds. The output in QEmu meets expectation, but the output in KVM is delayed for seconds. Per Avi's suggestion, I hooked flushing coalesced MMIO buffer in VGA update handler. By this way, We don't need vcpu explicit exit to QEmu to handle this issue. Signed-off-by: Sheng Yang Signed-off-by: Marcelo Tosatti --- cpu-all.h | 2 ++ exec.c | 6 ++++++ kvm-all.c | 23 +++++++++++++++-------- kvm.h | 1 + vl.c | 2 ++ 5 files changed, 26 insertions(+), 8 deletions(-) diff --git a/cpu-all.h b/cpu-all.h index 57b69f8865..1ccc9a87b7 100644 --- a/cpu-all.h +++ b/cpu-all.h @@ -915,6 +915,8 @@ void qemu_register_coalesced_mmio(target_phys_addr_t addr, ram_addr_t size); void qemu_unregister_coalesced_mmio(target_phys_addr_t addr, ram_addr_t size); +void qemu_flush_coalesced_mmio_buffer(void); + /*******************************************/ /* host CPU ticks (if available) */ diff --git a/exec.c b/exec.c index 76831a194f..67fabaef04 100644 --- a/exec.c +++ b/exec.c @@ -2406,6 +2406,12 @@ void qemu_unregister_coalesced_mmio(target_phys_addr_t addr, ram_addr_t size) kvm_uncoalesce_mmio_region(addr, size); } +void qemu_flush_coalesced_mmio_buffer(void) +{ + if (kvm_enabled()) + kvm_flush_coalesced_mmio_buffer(); +} + ram_addr_t qemu_ram_alloc(ram_addr_t size) { RAMBlock *new_block; diff --git a/kvm-all.c b/kvm-all.c index 15ec38e631..f8350c9580 100644 --- a/kvm-all.c +++ b/kvm-all.c @@ -59,6 +59,9 @@ struct KVMState int vmfd; int regs_modified; int coalesced_mmio; +#ifdef KVM_CAP_COALESCED_MMIO + struct kvm_coalesced_mmio_ring *coalesced_mmio_ring; +#endif int broken_set_mem_region; int migration_log; int vcpu_events; @@ -200,6 +203,12 @@ int kvm_init_vcpu(CPUState *env) goto err; } +#ifdef KVM_CAP_COALESCED_MMIO + if (s->coalesced_mmio && !s->coalesced_mmio_ring) + s->coalesced_mmio_ring = (void *) env->kvm_run + + s->coalesced_mmio * PAGE_SIZE; +#endif + ret = kvm_arch_init_vcpu(env); if (ret == 0) { qemu_register_reset(kvm_reset_vcpu, env); @@ -466,10 +475,10 @@ int kvm_init(int smp_cpus) goto err; } + s->coalesced_mmio = 0; #ifdef KVM_CAP_COALESCED_MMIO s->coalesced_mmio = kvm_check_extension(s, KVM_CAP_COALESCED_MMIO); -#else - s->coalesced_mmio = 0; + s->coalesced_mmio_ring = NULL; #endif s->broken_set_mem_region = 1; @@ -544,14 +553,12 @@ static int kvm_handle_io(uint16_t port, void *data, int direction, int size, return 1; } -static void kvm_run_coalesced_mmio(CPUState *env, struct kvm_run *run) +void kvm_flush_coalesced_mmio_buffer(void) { #ifdef KVM_CAP_COALESCED_MMIO KVMState *s = kvm_state; - if (s->coalesced_mmio) { - struct kvm_coalesced_mmio_ring *ring; - - ring = (void *)run + (s->coalesced_mmio * TARGET_PAGE_SIZE); + if (s->coalesced_mmio_ring) { + struct kvm_coalesced_mmio_ring *ring = s->coalesced_mmio_ring; while (ring->first != ring->last) { struct kvm_coalesced_mmio *ent; @@ -609,7 +616,7 @@ int kvm_cpu_exec(CPUState *env) abort(); } - kvm_run_coalesced_mmio(env, run); + kvm_flush_coalesced_mmio_buffer(); ret = 0; /* exit loop */ switch (run->exit_reason) { diff --git a/kvm.h b/kvm.h index 1c93ac5753..59cba18e96 100644 --- a/kvm.h +++ b/kvm.h @@ -53,6 +53,7 @@ void kvm_setup_guest_memory(void *start, size_t size); int kvm_coalesce_mmio_region(target_phys_addr_t start, ram_addr_t size); int kvm_uncoalesce_mmio_region(target_phys_addr_t start, ram_addr_t size); +void kvm_flush_coalesced_mmio_buffer(void); int kvm_insert_breakpoint(CPUState *current_env, target_ulong addr, target_ulong len, int type); diff --git a/vl.c b/vl.c index 39833fc3b3..50f133d496 100644 --- a/vl.c +++ b/vl.c @@ -2996,6 +2996,7 @@ static void gui_update(void *opaque) DisplayState *ds = opaque; DisplayChangeListener *dcl = ds->listeners; + qemu_flush_coalesced_mmio_buffer(); dpy_refresh(ds); while (dcl != NULL) { @@ -3011,6 +3012,7 @@ static void nographic_update(void *opaque) { uint64_t interval = GUI_REFRESH_INTERVAL; + qemu_flush_coalesced_mmio_buffer(); qemu_mod_timer(nographic_timer, interval + qemu_get_clock(rt_clock)); } From aee028b95d1d250a727583a14c864bc95ec27c69 Mon Sep 17 00:00:00 2001 From: Jan Kiszka Date: Thu, 28 Jan 2010 09:30:51 +0100 Subject: [PATCH 2/6] KVM: Request setting of nmi_pending and sipi_vector The final version of VCPU events in 2.6.33 will allow to skip nmi_pending and sipi_vector on KVM_SET_VCPU_EVENTS. For now let's write them unconditionally, which is unproblematic for upstream due to missing SMP support. Future version which enable SMP will write them only on reset. Signed-off-by: Jan Kiszka Signed-off-by: Marcelo Tosatti --- target-i386/kvm.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/target-i386/kvm.c b/target-i386/kvm.c index 5b093ce3bf..b457b96d46 100644 --- a/target-i386/kvm.c +++ b/target-i386/kvm.c @@ -794,6 +794,9 @@ static int kvm_put_vcpu_events(CPUState *env) events.sipi_vector = env->sipi_vector; + events.flags = + KVM_VCPUEVENT_VALID_NMI_PENDING | KVM_VCPUEVENT_VALID_SIPI_VECTOR; + return kvm_vcpu_ioctl(env, KVM_SET_VCPU_EVENTS, &events); #else return 0; From 19ccb8ea1799f6f29ba5bc37d5f18dc8050d4029 Mon Sep 17 00:00:00 2001 From: Jan Kiszka Date: Wed, 3 Feb 2010 21:16:37 +0100 Subject: [PATCH 3/6] KVM: x86: Fix up misreported CPU features From qemu-kvm: Kernels before 2.6.30 misreported some essential CPU features via KVM_GET_SUPPORTED_CPUID. Fix them up. Signed-off-by: Jan Kiszka --- target-i386/kvm.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/target-i386/kvm.c b/target-i386/kvm.c index b457b96d46..0d08cd532e 100644 --- a/target-i386/kvm.c +++ b/target-i386/kvm.c @@ -99,12 +99,18 @@ uint32_t kvm_arch_get_supported_cpuid(CPUState *env, uint32_t function, int reg) break; case R_EDX: ret = cpuid->entries[i].edx; - if (function == 0x80000001) { + switch (function) { + case 1: + /* KVM before 2.6.30 misreports the following features */ + ret |= CPUID_MTRR | CPUID_PAT | CPUID_MCE | CPUID_MCA; + break; + case 0x80000001: /* On Intel, kvm returns cpuid according to the Intel spec, * so add missing bits according to the AMD spec: */ cpuid_1_edx = kvm_arch_get_supported_cpuid(env, 1, R_EDX); ret |= cpuid_1_edx & 0xdfeff7ff; + break; } break; } From 03c63b945239dc4abcf3a687beda6eb3b0cd69bc Mon Sep 17 00:00:00 2001 From: Jan Kiszka Date: Wed, 3 Feb 2010 21:16:41 +0100 Subject: [PATCH 4/6] KVM: Make vmport KVM-compatible The vmport "device" accesses the VCPU registers, so it requires proper cpu_synchronize_state. Add it to vmport_ioport_read, which also synchronizes vmport_ioport_write. Signed-off-by: Jan Kiszka --- hw/vmport.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/hw/vmport.c b/hw/vmport.c index 884af3fd91..6c9d7c9651 100644 --- a/hw/vmport.c +++ b/hw/vmport.c @@ -25,6 +25,7 @@ #include "isa.h" #include "pc.h" #include "sysemu.h" +#include "kvm.h" //#define VMPORT_DEBUG @@ -58,6 +59,8 @@ static uint32_t vmport_ioport_read(void *opaque, uint32_t addr) unsigned char command; uint32_t eax; + cpu_synchronize_state(env); + eax = env->regs[R_EAX]; if (eax != VMPORT_MAGIC) return eax; From 9ded2744667292d020455f51664eb161a449c243 Mon Sep 17 00:00:00 2001 From: Jan Kiszka Date: Wed, 3 Feb 2010 21:17:05 +0100 Subject: [PATCH 5/6] KVM: Move and rename regs_modified Touching the user space representation of KVM's VCPU state is - naturally - a per-VCPU thing. So move the dirty flag into KVM_CPU_COMMON and rename it at this chance to reflect its true meaning. Signed-off-by: Jan Kiszka --- cpu-defs.h | 3 ++- kvm-all.c | 13 ++++++------- 2 files changed, 8 insertions(+), 8 deletions(-) diff --git a/cpu-defs.h b/cpu-defs.h index 95068b5304..7fdbe97787 100644 --- a/cpu-defs.h +++ b/cpu-defs.h @@ -197,6 +197,7 @@ typedef struct CPUWatchpoint { const char *cpu_model_str; \ struct KVMState *kvm_state; \ struct kvm_run *kvm_run; \ - int kvm_fd; + int kvm_fd; \ + int kvm_vcpu_dirty; #endif diff --git a/kvm-all.c b/kvm-all.c index f8350c9580..6c0fd373a2 100644 --- a/kvm-all.c +++ b/kvm-all.c @@ -57,7 +57,6 @@ struct KVMState KVMSlot slots[32]; int fd; int vmfd; - int regs_modified; int coalesced_mmio; #ifdef KVM_CAP_COALESCED_MMIO struct kvm_coalesced_mmio_ring *coalesced_mmio_ring; @@ -574,9 +573,9 @@ void kvm_flush_coalesced_mmio_buffer(void) void kvm_cpu_synchronize_state(CPUState *env) { - if (!env->kvm_state->regs_modified) { + if (!env->kvm_vcpu_dirty) { kvm_arch_get_registers(env); - env->kvm_state->regs_modified = 1; + env->kvm_vcpu_dirty = 1; } } @@ -594,9 +593,9 @@ int kvm_cpu_exec(CPUState *env) break; } - if (env->kvm_state->regs_modified) { + if (env->kvm_vcpu_dirty) { kvm_arch_put_registers(env); - env->kvm_state->regs_modified = 0; + env->kvm_vcpu_dirty = 0; } kvm_arch_pre_run(env, run); @@ -946,9 +945,9 @@ static void kvm_invoke_set_guest_debug(void *data) struct kvm_set_guest_debug_data *dbg_data = data; CPUState *env = dbg_data->env; - if (env->kvm_state->regs_modified) { + if (env->kvm_vcpu_dirty) { kvm_arch_put_registers(env); - env->kvm_state->regs_modified = 0; + env->kvm_vcpu_dirty = 0; } dbg_data->err = kvm_vcpu_ioctl(env, KVM_SET_GUEST_DEBUG, &dbg_data->dbg); } From c5f32c99c6855d466737daf1cd262e7e92062f87 Mon Sep 17 00:00:00 2001 From: Marcelo Tosatti Date: Wed, 3 Feb 2010 21:44:17 -0200 Subject: [PATCH 6/6] Fix incoming migration with iothread Do not allow the vcpus to execute if the vm is stopped. Fixes -incoming with CONFIG_IOTHREAD enabled. Signed-off-by: Marcelo Tosatti --- vl.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/vl.c b/vl.c index 50f133d496..57f0ba53df 100644 --- a/vl.c +++ b/vl.c @@ -3282,6 +3282,8 @@ static int cpu_can_run(CPUState *env) return 0; if (env->stopped) return 0; + if (!vm_running) + return 0; return 1; }