[PULL 20/24] kvm: i386: require KVM_CAP_SET_VCPU_EVENTS and KVM_CAP_X86_ROBUST_SINGLESTEP

[Paolo Bonzini <pbonzini@redhat.com>]

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 accel/kvm/kvm-all.c      |  9 ----
 include/sysemu/kvm.h     |  1 -
 include/sysemu/kvm_int.h |  1 -
 target/i386/kvm/kvm.c    | 92 +---------------------------------------
 4 files changed, 2 insertions(+), 101 deletions(-)

diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index aeda902b3e9..e39a810a4e9 100644
--- a/accel/kvm/kvm-all.c
+++ b/accel/kvm/kvm-all.c
@@ -2524,10 +2524,6 @@ static int kvm_init(MachineState *ms)
 #ifdef KVM_CAP_VCPU_EVENTS
     s->vcpu_events = kvm_check_extension(s, KVM_CAP_VCPU_EVENTS);
 #endif
-
-    s->robust_singlestep =
-        kvm_check_extension(s, KVM_CAP_X86_ROBUST_SINGLESTEP);
-
     s->max_nested_state_len = kvm_check_extension(s, KVM_CAP_NESTED_STATE);
 
     s->irq_set_ioctl = KVM_IRQ_LINE;
@@ -3143,11 +3139,6 @@ int kvm_has_vcpu_events(void)
     return kvm_state->vcpu_events;
 }
 
-int kvm_has_robust_singlestep(void)
-{
-    return kvm_state->robust_singlestep;
-}
-
 int kvm_max_nested_state_length(void)
 {
     return kvm_state->max_nested_state_len;
diff --git a/include/sysemu/kvm.h b/include/sysemu/kvm.h
index 02c031d1f29..80b69d88f6e 100644
--- a/include/sysemu/kvm.h
+++ b/include/sysemu/kvm.h
@@ -192,7 +192,6 @@ unsigned int kvm_get_max_memslots(void);
 unsigned int kvm_get_free_memslots(void);
 bool kvm_has_sync_mmu(void);
 int kvm_has_vcpu_events(void);
-int kvm_has_robust_singlestep(void);
 int kvm_max_nested_state_length(void);
 int kvm_has_gsi_routing(void);
 
diff --git a/include/sysemu/kvm_int.h b/include/sysemu/kvm_int.h
index 151ecc84233..fd846394be1 100644
--- a/include/sysemu/kvm_int.h
+++ b/include/sysemu/kvm_int.h
@@ -78,7 +78,6 @@ struct KVMState
     struct kvm_coalesced_mmio_ring *coalesced_mmio_ring;
     bool coalesced_flush_in_progress;
     int vcpu_events;
-    int robust_singlestep;
 #ifdef KVM_CAP_SET_GUEST_DEBUG
     QTAILQ_HEAD(, kvm_sw_breakpoint) kvm_sw_breakpoints;
 #endif
diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
index 513a90f6307..4a244174a0f 100644
--- a/target/i386/kvm/kvm.c
+++ b/target/i386/kvm/kvm.c
@@ -95,6 +95,8 @@ const KVMCapabilityInfo kvm_arch_required_capabilities[] = {
     KVM_CAP_INFO(IRQ_ROUTING),
     KVM_CAP_INFO(DEBUGREGS),
     KVM_CAP_INFO(XSAVE),
+    KVM_CAP_INFO(VCPU_EVENTS),
+    KVM_CAP_INFO(X86_ROBUST_SINGLESTEP),
     KVM_CAP_LAST_INFO
 };
 
@@ -690,15 +692,6 @@ void kvm_arch_on_sigbus_vcpu(CPUState *c, int code, void *addr)
     emit_hypervisor_memory_failure(MEMORY_FAILURE_ACTION_IGNORE, false);
 }
 
-static void kvm_reset_exception(CPUX86State *env)
-{
-    env->exception_nr = -1;
-    env->exception_pending = 0;
-    env->exception_injected = 0;
-    env->exception_has_payload = false;
-    env->exception_payload = 0;
-}
-
 static void kvm_queue_exception(CPUX86State *env,
                                 int32_t exception_nr,
                                 uint8_t exception_has_payload,
@@ -731,38 +724,6 @@ static void kvm_queue_exception(CPUX86State *env,
     }
 }
 
-static int kvm_inject_mce_oldstyle(X86CPU *cpu)
-{
-    CPUX86State *env = &cpu->env;
-
-    if (!kvm_has_vcpu_events() && env->exception_nr == EXCP12_MCHK) {
-        unsigned int bank, bank_num = env->mcg_cap & 0xff;
-        struct kvm_x86_mce mce;
-
-        kvm_reset_exception(env);
-
-        /*
-         * There must be at least one bank in use if an MCE is pending.
-         * Find it and use its values for the event injection.
-         */
-        for (bank = 0; bank < bank_num; bank++) {
-            if (env->mce_banks[bank * 4 + 1] & MCI_STATUS_VAL) {
-                break;
-            }
-        }
-        assert(bank < bank_num);
-
-        mce.bank = bank;
-        mce.status = env->mce_banks[bank * 4 + 1];
-        mce.mcg_status = env->mcg_status;
-        mce.addr = env->mce_banks[bank * 4 + 2];
-        mce.misc = env->mce_banks[bank * 4 + 3];
-
-        return kvm_vcpu_ioctl(CPU(cpu), KVM_X86_SET_MCE, &mce);
-    }
-    return 0;
-}
-
 static void cpu_update_state(void *opaque, bool running, RunState state)
 {
     CPUX86State *env = opaque;
@@ -4359,10 +4320,6 @@ static int kvm_put_vcpu_events(X86CPU *cpu, int level)
     CPUX86State *env = &cpu->env;
     struct kvm_vcpu_events events = {};
 
-    if (!kvm_has_vcpu_events()) {
-        return 0;
-    }
-
     events.flags = 0;
 
     if (has_exception_payload) {
@@ -4430,10 +4387,6 @@ static int kvm_get_vcpu_events(X86CPU *cpu)
     struct kvm_vcpu_events events;
     int ret;
 
-    if (!kvm_has_vcpu_events()) {
-        return 0;
-    }
-
     memset(&events, 0, sizeof(events));
     ret = kvm_vcpu_ioctl(CPU(cpu), KVM_GET_VCPU_EVENTS, &events);
     if (ret < 0) {
@@ -4499,37 +4452,6 @@ static int kvm_get_vcpu_events(X86CPU *cpu)
     return 0;
 }
 
-static int kvm_guest_debug_workarounds(X86CPU *cpu)
-{
-    CPUState *cs = CPU(cpu);
-    CPUX86State *env = &cpu->env;
-    int ret = 0;
-    unsigned long reinject_trap = 0;
-
-    if (!kvm_has_vcpu_events()) {
-        if (env->exception_nr == EXCP01_DB) {
-            reinject_trap = KVM_GUESTDBG_INJECT_DB;
-        } else if (env->exception_injected == EXCP03_INT3) {
-            reinject_trap = KVM_GUESTDBG_INJECT_BP;
-        }
-        kvm_reset_exception(env);
-    }
-
-    /*
-     * Kernels before KVM_CAP_X86_ROBUST_SINGLESTEP overwrote flags.TF
-     * injected via SET_GUEST_DEBUG while updating GP regs. Work around this
-     * by updating the debug state once again if single-stepping is on.
-     * Another reason to call kvm_update_guest_debug here is a pending debug
-     * trap raise by the guest. On kernels without SET_VCPU_EVENTS we have to
-     * reinject them via SET_GUEST_DEBUG.
-     */
-    if (reinject_trap ||
-        (!kvm_has_robust_singlestep() && cs->singlestep_enabled)) {
-        ret = kvm_update_guest_debug(cs, reinject_trap);
-    }
-    return ret;
-}
-
 static int kvm_put_debugregs(X86CPU *cpu)
 {
     CPUX86State *env = &cpu->env;
@@ -4702,11 +4624,6 @@ int kvm_arch_put_registers(CPUState *cpu, int level)
     if (ret < 0) {
         return ret;
     }
-    /* must be before kvm_put_msrs */
-    ret = kvm_inject_mce_oldstyle(x86_cpu);
-    if (ret < 0) {
-        return ret;
-    }
     ret = kvm_put_msrs(x86_cpu, level);
     if (ret < 0) {
         return ret;
@@ -4730,11 +4647,6 @@ int kvm_arch_put_registers(CPUState *cpu, int level)
     if (ret < 0) {
         return ret;
     }
-    /* must be last */
-    ret = kvm_guest_debug_workarounds(x86_cpu);
-    if (ret < 0) {
-        return ret;
-    }
     return 0;
 }
 
-- 
2.41.0