[PULL 19/23] kvm: Allow kvm_arch_get/put_registers to accept Error**

[Paolo Bonzini <pbonzini@redhat.com>]

From: Julia Suvorova <jusual@redhat.com>

This is necessary to provide discernible error messages to the caller.

Signed-off-by: Julia Suvorova <jusual@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Link: https://lore.kernel.org/r/20240927104743.218468-2-jusual@redhat.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 include/sysemu/kvm.h       |  4 ++--
 accel/kvm/kvm-all.c        | 41 +++++++++++++++++++++++++++++---------
 target/arm/kvm.c           |  4 ++--
 target/i386/kvm/kvm.c      |  4 ++--
 target/loongarch/kvm/kvm.c |  4 ++--
 target/mips/kvm.c          |  4 ++--
 target/ppc/kvm.c           |  4 ++--
 target/riscv/kvm/kvm-cpu.c |  4 ++--
 target/s390x/kvm/kvm.c     |  4 ++--
 9 files changed, 48 insertions(+), 25 deletions(-)

diff --git a/include/sysemu/kvm.h b/include/sysemu/kvm.h
index 613d3f7581f..c3a60b28909 100644
--- a/include/sysemu/kvm.h
+++ b/include/sysemu/kvm.h
@@ -359,7 +359,7 @@ int kvm_arch_handle_exit(CPUState *cpu, struct kvm_run *run);
 
 int kvm_arch_process_async_events(CPUState *cpu);
 
-int kvm_arch_get_registers(CPUState *cpu);
+int kvm_arch_get_registers(CPUState *cpu, Error **errp);
 
 /* state subset only touched by the VCPU itself during runtime */
 #define KVM_PUT_RUNTIME_STATE   1
@@ -368,7 +368,7 @@ int kvm_arch_get_registers(CPUState *cpu);
 /* full state set, modified during initialization or on vmload */
 #define KVM_PUT_FULL_STATE      3
 
-int kvm_arch_put_registers(CPUState *cpu, int level);
+int kvm_arch_put_registers(CPUState *cpu, int level, Error **errp);
 
 int kvm_arch_get_default_type(MachineState *ms);
 
diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index e57492fda5c..905fb844e46 100644
--- a/accel/kvm/kvm-all.c
+++ b/accel/kvm/kvm-all.c
@@ -2793,9 +2793,15 @@ void kvm_flush_coalesced_mmio_buffer(void)
 static void do_kvm_cpu_synchronize_state(CPUState *cpu, run_on_cpu_data arg)
 {
     if (!cpu->vcpu_dirty && !kvm_state->guest_state_protected) {
-        int ret = kvm_arch_get_registers(cpu);
+        Error *err = NULL;
+        int ret = kvm_arch_get_registers(cpu, &err);
         if (ret) {
-            error_report("Failed to get registers: %s", strerror(-ret));
+            if (err) {
+                error_reportf_err(err, "Failed to synchronize CPU state: ");
+            } else {
+                error_report("Failed to get registers: %s", strerror(-ret));
+            }
+
             cpu_dump_state(cpu, stderr, CPU_DUMP_CODE);
             vm_stop(RUN_STATE_INTERNAL_ERROR);
         }
@@ -2813,9 +2819,15 @@ void kvm_cpu_synchronize_state(CPUState *cpu)
 
 static void do_kvm_cpu_synchronize_post_reset(CPUState *cpu, run_on_cpu_data arg)
 {
-    int ret = kvm_arch_put_registers(cpu, KVM_PUT_RESET_STATE);
+    Error *err = NULL;
+    int ret = kvm_arch_put_registers(cpu, KVM_PUT_RESET_STATE, &err);
     if (ret) {
-        error_report("Failed to put registers after reset: %s", strerror(-ret));
+        if (err) {
+            error_reportf_err(err, "Restoring resisters after reset: ");
+        } else {
+            error_report("Failed to put registers after reset: %s",
+                         strerror(-ret));
+        }
         cpu_dump_state(cpu, stderr, CPU_DUMP_CODE);
         vm_stop(RUN_STATE_INTERNAL_ERROR);
     }
@@ -2830,9 +2842,15 @@ void kvm_cpu_synchronize_post_reset(CPUState *cpu)
 
 static void do_kvm_cpu_synchronize_post_init(CPUState *cpu, run_on_cpu_data arg)
 {
-    int ret = kvm_arch_put_registers(cpu, KVM_PUT_FULL_STATE);
+    Error *err = NULL;
+    int ret = kvm_arch_put_registers(cpu, KVM_PUT_FULL_STATE, &err);
     if (ret) {
-        error_report("Failed to put registers after init: %s", strerror(-ret));
+        if (err) {
+            error_reportf_err(err, "Putting registers after init: ");
+        } else {
+            error_report("Failed to put registers after init: %s",
+                         strerror(-ret));
+        }
         exit(1);
     }
 
@@ -3022,10 +3040,15 @@ int kvm_cpu_exec(CPUState *cpu)
         MemTxAttrs attrs;
 
         if (cpu->vcpu_dirty) {
-            ret = kvm_arch_put_registers(cpu, KVM_PUT_RUNTIME_STATE);
+            Error *err = NULL;
+            ret = kvm_arch_put_registers(cpu, KVM_PUT_RUNTIME_STATE, &err);
             if (ret) {
-                error_report("Failed to put registers after init: %s",
-                             strerror(-ret));
+                if (err) {
+                    error_reportf_err(err, "Putting registers after init: ");
+                } else {
+                    error_report("Failed to put registers after init: %s",
+                                 strerror(-ret));
+                }
                 ret = -1;
                 break;
             }
diff --git a/target/arm/kvm.c b/target/arm/kvm.c
index 849e2e21b30..f1f1b5b375a 100644
--- a/target/arm/kvm.c
+++ b/target/arm/kvm.c
@@ -2042,7 +2042,7 @@ static int kvm_arch_put_sve(CPUState *cs)
     return 0;
 }
 
-int kvm_arch_put_registers(CPUState *cs, int level)
+int kvm_arch_put_registers(CPUState *cs, int level, Error **errp)
 {
     uint64_t val;
     uint32_t fpr;
@@ -2226,7 +2226,7 @@ static int kvm_arch_get_sve(CPUState *cs)
     return 0;
 }
 
-int kvm_arch_get_registers(CPUState *cs)
+int kvm_arch_get_registers(CPUState *cs, Error **errp)
 {
     uint64_t val;
     unsigned int el;
diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
index 7a1f2bda767..0b03fb0577f 100644
--- a/target/i386/kvm/kvm.c
+++ b/target/i386/kvm/kvm.c
@@ -5210,7 +5210,7 @@ static int kvm_get_nested_state(X86CPU *cpu)
     return ret;
 }
 
-int kvm_arch_put_registers(CPUState *cpu, int level)
+int kvm_arch_put_registers(CPUState *cpu, int level, Error **errp)
 {
     X86CPU *x86_cpu = X86_CPU(cpu);
     int ret;
@@ -5298,7 +5298,7 @@ int kvm_arch_put_registers(CPUState *cpu, int level)
     return 0;
 }
 
-int kvm_arch_get_registers(CPUState *cs)
+int kvm_arch_get_registers(CPUState *cs, Error **errp)
 {
     X86CPU *cpu = X86_CPU(cs);
     int ret;
diff --git a/target/loongarch/kvm/kvm.c b/target/loongarch/kvm/kvm.c
index 4786cd5efa4..30ec16025d4 100644
--- a/target/loongarch/kvm/kvm.c
+++ b/target/loongarch/kvm/kvm.c
@@ -588,7 +588,7 @@ static int kvm_loongarch_put_cpucfg(CPUState *cs)
     return ret;
 }
 
-int kvm_arch_get_registers(CPUState *cs)
+int kvm_arch_get_registers(CPUState *cs, Error **errp)
 {
     int ret;
 
@@ -616,7 +616,7 @@ int kvm_arch_get_registers(CPUState *cs)
     return ret;
 }
 
-int kvm_arch_put_registers(CPUState *cs, int level)
+int kvm_arch_put_registers(CPUState *cs, int level, Error **errp)
 {
     int ret;
 
diff --git a/target/mips/kvm.c b/target/mips/kvm.c
index a631ab544f5..a98798c6691 100644
--- a/target/mips/kvm.c
+++ b/target/mips/kvm.c
@@ -1172,7 +1172,7 @@ static int kvm_mips_get_cp0_registers(CPUState *cs)
     return ret;
 }
 
-int kvm_arch_put_registers(CPUState *cs, int level)
+int kvm_arch_put_registers(CPUState *cs, int level, Error **errp)
 {
     CPUMIPSState *env = cpu_env(cs);
     struct kvm_regs regs;
@@ -1207,7 +1207,7 @@ int kvm_arch_put_registers(CPUState *cs, int level)
     return ret;
 }
 
-int kvm_arch_get_registers(CPUState *cs)
+int kvm_arch_get_registers(CPUState *cs, Error **errp)
 {
     CPUMIPSState *env = cpu_env(cs);
     int ret = 0;
diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c
index 907dba60d1b..3efc28f18b3 100644
--- a/target/ppc/kvm.c
+++ b/target/ppc/kvm.c
@@ -900,7 +900,7 @@ int kvmppc_put_books_sregs(PowerPCCPU *cpu)
     return kvm_vcpu_ioctl(CPU(cpu), KVM_SET_SREGS, &sregs);
 }
 
-int kvm_arch_put_registers(CPUState *cs, int level)
+int kvm_arch_put_registers(CPUState *cs, int level, Error **errp)
 {
     PowerPCCPU *cpu = POWERPC_CPU(cs);
     CPUPPCState *env = &cpu->env;
@@ -1205,7 +1205,7 @@ static int kvmppc_get_books_sregs(PowerPCCPU *cpu)
     return 0;
 }
 
-int kvm_arch_get_registers(CPUState *cs)
+int kvm_arch_get_registers(CPUState *cs, Error **errp)
 {
     PowerPCCPU *cpu = POWERPC_CPU(cs);
     CPUPPCState *env = &cpu->env;
diff --git a/target/riscv/kvm/kvm-cpu.c b/target/riscv/kvm/kvm-cpu.c
index f6e3156b8d2..2bfb112be08 100644
--- a/target/riscv/kvm/kvm-cpu.c
+++ b/target/riscv/kvm/kvm-cpu.c
@@ -1192,7 +1192,7 @@ const KVMCapabilityInfo kvm_arch_required_capabilities[] = {
     KVM_CAP_LAST_INFO
 };
 
-int kvm_arch_get_registers(CPUState *cs)
+int kvm_arch_get_registers(CPUState *cs, Error **errp)
 {
     int ret = 0;
 
@@ -1237,7 +1237,7 @@ int kvm_riscv_sync_mpstate_to_kvm(RISCVCPU *cpu, int state)
     return 0;
 }
 
-int kvm_arch_put_registers(CPUState *cs, int level)
+int kvm_arch_put_registers(CPUState *cs, int level, Error **errp)
 {
     int ret = 0;
 
diff --git a/target/s390x/kvm/kvm.c b/target/s390x/kvm/kvm.c
index 94181d9281f..8ffe0159d82 100644
--- a/target/s390x/kvm/kvm.c
+++ b/target/s390x/kvm/kvm.c
@@ -472,7 +472,7 @@ static int can_sync_regs(CPUState *cs, int regs)
 #define KVM_SYNC_REQUIRED_REGS (KVM_SYNC_GPRS | KVM_SYNC_ACRS | \
                                 KVM_SYNC_CRS | KVM_SYNC_PREFIX)
 
-int kvm_arch_put_registers(CPUState *cs, int level)
+int kvm_arch_put_registers(CPUState *cs, int level, Error **errp)
 {
     CPUS390XState *env = cpu_env(cs);
     struct kvm_fpu fpu = {};
@@ -598,7 +598,7 @@ int kvm_arch_put_registers(CPUState *cs, int level)
     return 0;
 }
 
-int kvm_arch_get_registers(CPUState *cs)
+int kvm_arch_get_registers(CPUState *cs, Error **errp)
 {
     CPUS390XState *env = cpu_env(cs);
     struct kvm_fpu fpu;
-- 
2.46.1