[Qemu-devel] [PATCH 4/7 v2] KVM regsync: Add register bitmap parameter to do_kvm_cpu_synchronize_state

["Jason J. Herne" <jjherne@us.ibm.com>]

From: "Jason J. Herne" <jjherne@us.ibm.com>

do_kvm_cpu_synchronize_state is called via run_on_cpu, so we can only pass
a single argument.  Create SyncStateArgs struct for this purpose and add
register bitmap data member to it.

Signed-off-by: Jason J. Herne <jjherne@us.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
---
 include/sysemu/kvm.h |    6 ++++++
 kvm-all.c            |   27 +++++++++++++++++----------
 2 files changed, 23 insertions(+), 10 deletions(-)

diff --git a/include/sysemu/kvm.h b/include/sysemu/kvm.h
index e0738ba..193d1f4 100644
--- a/include/sysemu/kvm.h
+++ b/include/sysemu/kvm.h
@@ -223,6 +223,12 @@ int kvm_check_extension(KVMState *s, unsigned int extension);
 
 uint32_t kvm_arch_get_supported_cpuid(KVMState *env, uint32_t function,
                                       uint32_t index, int reg);
+
+struct kvm_cpu_syncstate_args {
+    CPUState *cpu;
+    int regmap;
+};
+
 void kvm_cpu_synchronize_state(CPUArchState *env);
 void kvm_cpu_synchronize_post_reset(CPUArchState *env);
 void kvm_cpu_synchronize_post_init(CPUArchState *env);
diff --git a/kvm-all.c b/kvm-all.c
index 1aa61bb..77ab72a 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -231,7 +231,7 @@ int kvm_init_vcpu(CPUArchState *env)
 
     cpu->kvm_fd = ret;
     cpu->kvm_state = s;
-    cpu->kvm_vcpu_dirty = true;
+    cpu->kvm_vcpu_dirty = KVM_REGSYNC_FULL_STATE;
 
     mmap_size = kvm_ioctl(s, KVM_GET_VCPU_MMAP_SIZE, 0);
     if (mmap_size < 0) {
@@ -1491,20 +1491,27 @@ void kvm_flush_coalesced_mmio_buffer(void)
 
 static void do_kvm_cpu_synchronize_state(void *arg)
 {
-    CPUState *cpu = arg;
+    struct kvm_cpu_syncstate_args *args = arg;
 
-    if (!cpu->kvm_vcpu_dirty) {
-        kvm_arch_get_registers(cpu, KVM_REGSYNC_FULL_STATE);
-        cpu->kvm_vcpu_dirty = true;
+    /* Do not sync regs that are already dirty */
+    int regs_to_get = args->regmap & ~args->cpu->kvm_vcpu_dirty;
+
+    if (regs_to_get) {
+        kvm_arch_get_registers(args->cpu, regs_to_get);
+        args->cpu->kvm_vcpu_dirty |= regs_to_get;
     }
 }
 
 void kvm_cpu_synchronize_state(CPUArchState *env)
 {
     CPUState *cpu = ENV_GET_CPU(env);
+    struct kvm_cpu_syncstate_args args;
+
+    args.cpu = cpu;
+    args.regmap = KVM_REGSYNC_FULL_STATE;
 
-    if (!cpu->kvm_vcpu_dirty) {
-        run_on_cpu(cpu, do_kvm_cpu_synchronize_state, cpu);
+    if (args.regmap & ~cpu->kvm_vcpu_dirty) {
+        run_on_cpu(cpu, do_kvm_cpu_synchronize_state, &args);
     }
 }
 
@@ -1513,7 +1520,7 @@ void kvm_cpu_synchronize_post_reset(CPUArchState *env)
     CPUState *cpu = ENV_GET_CPU(env);
 
     kvm_arch_put_registers(cpu, KVM_REGSYNC_RESET_STATE);
-    cpu->kvm_vcpu_dirty = false;
+    cpu->kvm_vcpu_dirty &= ~KVM_REGSYNC_RESET_STATE;
 }
 
 void kvm_cpu_synchronize_post_init(CPUArchState *env)
@@ -1521,7 +1528,7 @@ void kvm_cpu_synchronize_post_init(CPUArchState *env)
     CPUState *cpu = ENV_GET_CPU(env);
 
     kvm_arch_put_registers(cpu, KVM_REGSYNC_FULL_STATE);
-    cpu->kvm_vcpu_dirty = false;
+    cpu->kvm_vcpu_dirty &= ~KVM_REGSYNC_FULL_STATE;
 }
 
 int kvm_cpu_exec(CPUArchState *env)
@@ -1540,7 +1547,7 @@ int kvm_cpu_exec(CPUArchState *env)
     do {
         if (cpu->kvm_vcpu_dirty) {
             kvm_arch_put_registers(cpu, KVM_REGSYNC_RUNTIME_STATE);
-            cpu->kvm_vcpu_dirty = false;
+            cpu->kvm_vcpu_dirty &= ~KVM_REGSYNC_RUNTIME_STATE;
         }
 
         kvm_arch_pre_run(cpu, run);
-- 
1.7.9.5