qemu/i386-kvm-extend-kvm_-get-put-_vcpu_events-to-support.patch

From 752fe0479931f6ef512b6a048fb50364505ff713 Mon Sep 17 00:00:00 2001
From: Chenyi Qiang <chenyi.qiang@intel.com>
Date: Thu, 29 Sep 2022 15:20:11 +0800
Subject: [PATCH] i386: kvm: extend kvm_{get, put}_vcpu_events to support
 pending triple fault

from mainline-v7.2.0-rc0
commit 12f89a39cf3c5760cba82ce68929d748961f62df
category: feature
feature: Notify VM Exit
bugzilla: https://gitee.com/openeuler/intel-qemu/issues/I6GWQE

Intel-SIG: commit 12f89a39cf3c ("i386: kvm: extend kvm_{get, put}_vcpu_events to support pending triple fault")

------------------------------------------------------------------

i386: kvm: extend kvm_{get, put}_vcpu_events to support pending triple fault

For the direct triple faults, i.e. hardware detected and KVM morphed
to VM-Exit, KVM will never lose them. But for triple faults sythesized
by KVM, e.g. the RSM path, if KVM exits to userspace before the request
is serviced, userspace could migrate the VM and lose the triple fault.

A new flag KVM_VCPUEVENT_VALID_TRIPLE_FAULT is defined to signal that
the event.triple_fault_pending field contains a valid state if the
KVM_CAP_X86_TRIPLE_FAULT_EVENT capability is enabled.

Acked-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Chenyi Qiang <chenyi.qiang@intel.com>
Message-Id: <20220929072014.20705-2-chenyi.qiang@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Jason Zeng <jason.zeng@intel.com>
---
 target/i386/cpu.c     |  1 +
 target/i386/cpu.h     |  1 +
 target/i386/kvm/kvm.c | 20 ++++++++++++++++++++
 target/i386/machine.c | 20 ++++++++++++++++++++
 4 files changed, 42 insertions(+)

diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index 551b47ab1e..e3cea8397c 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -6018,6 +6018,7 @@ static void x86_cpu_reset(DeviceState *dev)
     env->exception_has_payload = false;
     env->exception_payload = 0;
     env->nmi_injected = false;
+    env->triple_fault_pending = false;
 #if !defined(CONFIG_USER_ONLY)
     /* We hard-wire the BSP to the first CPU. */
     apic_designate_bsp(cpu->apic_state, s->cpu_index == 0);
diff --git a/target/i386/cpu.h b/target/i386/cpu.h
index 290f1beaea..4f7fa87b95 100644
--- a/target/i386/cpu.h
+++ b/target/i386/cpu.h
@@ -1698,6 +1698,7 @@ typedef struct CPUX86State {
     uint8_t has_error_code;
     uint8_t exception_has_payload;
     uint64_t exception_payload;
+    uint8_t triple_fault_pending;
     uint32_t ins_len;
     uint32_t sipi_vector;
     bool tsc_valid;
diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
index 5b15e0430b..e97d967c73 100644
--- a/target/i386/kvm/kvm.c
+++ b/target/i386/kvm/kvm.c
@@ -127,6 +127,7 @@ static int has_xsave2;
 static int has_xcrs;
 static int has_pit_state2;
 static int has_exception_payload;
+static int has_triple_fault_event;
 
 static bool has_msr_mcg_ext_ctl;
 
@@ -2380,6 +2381,16 @@ int kvm_arch_init(MachineState *ms, KVMState *s)
         }
     }
 
+    has_triple_fault_event = kvm_check_extension(s, KVM_CAP_X86_TRIPLE_FAULT_EVENT);
+    if (has_triple_fault_event) {
+        ret = kvm_vm_enable_cap(s, KVM_CAP_X86_TRIPLE_FAULT_EVENT, 0, true);
+        if (ret < 0) {
+            error_report("kvm: Failed to enable triple fault event cap: %s",
+                         strerror(-ret));
+            return ret;
+        }
+    }
+
     ret = kvm_get_supported_msrs(s);
     if (ret < 0) {
         return ret;
@@ -4004,6 +4015,11 @@ static int kvm_put_vcpu_events(X86CPU *cpu, int level)
         }
     }
 
+    if (has_triple_fault_event) {
+        events.flags |= KVM_VCPUEVENT_VALID_TRIPLE_FAULT;
+        events.triple_fault.pending = env->triple_fault_pending;
+    }
+
     return kvm_vcpu_ioctl(CPU(cpu), KVM_SET_VCPU_EVENTS, &events);
 }
 
@@ -4073,6 +4089,10 @@ static int kvm_get_vcpu_events(X86CPU *cpu)
         }
     }
 
+    if (events.flags & KVM_VCPUEVENT_VALID_TRIPLE_FAULT) {
+        env->triple_fault_pending = events.triple_fault.pending;
+    }
+
     env->sipi_vector = events.sipi_vector;
 
     return 0;
diff --git a/target/i386/machine.c b/target/i386/machine.c
index 3977e9d8f8..41cf5c0053 100644
--- a/target/i386/machine.c
+++ b/target/i386/machine.c
@@ -1497,6 +1497,25 @@ static const VMStateDescription vmstate_amx_xtile = {
 };
 #endif
 
+static bool triple_fault_needed(void *opaque)
+{
+    X86CPU *cpu = opaque;
+    CPUX86State *env = &cpu->env;
+
+    return env->triple_fault_pending;
+}
+
+static const VMStateDescription vmstate_triple_fault = {
+    .name = "cpu/triple_fault",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .needed = triple_fault_needed,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT8(env.triple_fault_pending, X86CPU),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
 const VMStateDescription vmstate_x86_cpu = {
     .name = "cpu",
     .version_id = 12,
@@ -1639,6 +1658,7 @@ const VMStateDescription vmstate_x86_cpu = {
 #ifdef TARGET_X86_64
         &vmstate_amx_xtile,
 #endif
+        &vmstate_triple_fault,
         NULL
     }
 };
-- 
2.27.0