Hello Thomas,
On 8/28/23 20:20, Thomas Huth wrote:
On 14/08/2023 21.06, Thomas Huth wrote:
KVM_SYNC_GPRS, KVM_SYNC_ACRS, KVM_SYNC_CRS and KVM_SYNC_PREFIX are
available since kernel 3.10. Since we already require at least kernel
3.15 in the s390x KVM code, we can assume that the KVM_CAP_SYNC_REGS
sync code is always possible for these registers, and remove the
related checks and fallbacks via KVM_SET_REGS and KVM_GET_REGS.
Signed-off-by: Thomas Huth <th...@redhat.com>
---
target/s390x/kvm/kvm.c | 119 ++++++++++++-----------------------------
1 file changed, 34 insertions(+), 85 deletions(-)
Ping! Anybody any comments on this one?
Only minor comments, see below.
Thomas
diff --git a/target/s390x/kvm/kvm.c b/target/s390x/kvm/kvm.c
index a9e5880349..ff415f7b30 100644
--- a/target/s390x/kvm/kvm.c
+++ b/target/s390x/kvm/kvm.c
@@ -148,7 +148,6 @@ const KVMCapabilityInfo kvm_arch_required_capabilities[] = {
KVM_CAP_LAST_INFO
};
-static int cap_sync_regs;
static int cap_async_pf;
static int cap_mem_op;
static int cap_mem_op_extension;
@@ -342,21 +341,28 @@ static void ccw_machine_class_foreach(ObjectClass *oc,
void *opaque)
int kvm_arch_init(MachineState *ms, KVMState *s)
{
+ int required_caps[] = {
+ KVM_CAP_DEVICE_CTRL,
+ KVM_CAP_SYNC_REGS,
+ };
+
+ for (int i = 0; i < ARRAY_SIZE(required_caps); i++) {
+ if (!kvm_check_extension(s, required_caps[i])) {
+ error_report("KVM is missing capability #%d - "
+ "please use kernel 3.15 or newer", required_caps[i]);
+ return -1;
+ }
+ }
+
object_class_foreach(ccw_machine_class_foreach, TYPE_S390_CCW_MACHINE,
false, NULL);
- if (!kvm_check_extension(kvm_state, KVM_CAP_DEVICE_CTRL)) {
- error_report("KVM is missing capability KVM_CAP_DEVICE_CTRL - "
- "please use kernel 3.15 or newer");
- return -1;
- }
if (!kvm_check_extension(s, KVM_CAP_S390_COW)) {
error_report("KVM is missing capability KVM_CAP_S390_COW - "
"unsupported environment");
return -1;
}
- cap_sync_regs = kvm_check_extension(s, KVM_CAP_SYNC_REGS);
cap_async_pf = kvm_check_extension(s, KVM_CAP_ASYNC_PF);
cap_mem_op = kvm_check_extension(s, KVM_CAP_S390_MEM_OP);
cap_mem_op_extension = kvm_check_extension(s,
KVM_CAP_S390_MEM_OP_EXTENSION);
I would introduce a first patch for the changes above, checking the
KVM capabilities, and a second for get/put register changes.
@@ -463,15 +469,15 @@ void kvm_s390_reset_vcpu_normal(S390CPU *cpu)
static int can_sync_regs(CPUState *cs, int regs)
{
- return cap_sync_regs && (cs->kvm_run->kvm_valid_regs & regs) == regs;
+ return (cs->kvm_run->kvm_valid_regs & regs) == regs;
}
int kvm_arch_put_registers(CPUState *cs, int level)
{
+ const int required_syncs = KVM_SYNC_GPRS | KVM_SYNC_ACRS |
+ KVM_SYNC_CRS | KVM_SYNC_PREFIX;
May be introduce a KVM_SYNC_s390_REQUIRED_FIELDS define for these fields,
as we already have KVM_SYNC_S390_VALID_FIELDS.
S390CPU *cpu = S390_CPU(cs);
CPUS390XState *env = &cpu->env;
- struct kvm_sregs sregs;
- struct kvm_regs regs;
struct kvm_fpu fpu = {};
int r;
int i;
@@ -480,21 +486,16 @@ int kvm_arch_put_registers(CPUState *cs, int level)
cs->kvm_run->psw_addr = env->psw.addr;
cs->kvm_run->psw_mask = env->psw.mask;
- if (can_sync_regs(cs, KVM_SYNC_GPRS)) {
- for (i = 0; i < 16; i++) {
- cs->kvm_run->s.regs.gprs[i] = env->regs[i];
- cs->kvm_run->kvm_dirty_regs |= KVM_SYNC_GPRS;
- }
- } else {
- for (i = 0; i < 16; i++) {
- regs.gprs[i] = env->regs[i];
- }
- r = kvm_vcpu_ioctl(cs, KVM_SET_REGS, ®s);
- if (r < 0) {
- return r;
- }
+ g_assert((cs->kvm_run->kvm_valid_regs & required_syncs) == required_syncs);
this also is :
g_assert(can_sync_regs(cs, KVM_SYNC_s390_REQUIRED_FIELDS));
the rest looks good.
Thanks,
C.
+ cs->kvm_run->kvm_dirty_regs |= required_syncs;
+ for (i = 0; i < 16; i++) {
+ cs->kvm_run->s.regs.gprs[i] = env->regs[i];
+ cs->kvm_run->s.regs.acrs[i] = env->aregs[i];
+ cs->kvm_run->s.regs.crs[i] = env->cregs[i];
}
+ cs->kvm_run->s.regs.prefix = env->psa;
+
if (can_sync_regs(cs, KVM_SYNC_VRS)) {
for (i = 0; i < 32; i++) {
cs->kvm_run->s.regs.vrs[i][0] = env->vregs[i][0];
@@ -572,25 +573,6 @@ int kvm_arch_put_registers(CPUState *cs, int level)
}
}
- /* access registers and control registers*/
- if (can_sync_regs(cs, KVM_SYNC_ACRS | KVM_SYNC_CRS)) {
- for (i = 0; i < 16; i++) {
- cs->kvm_run->s.regs.acrs[i] = env->aregs[i];
- cs->kvm_run->s.regs.crs[i] = env->cregs[i];
- }
- cs->kvm_run->kvm_dirty_regs |= KVM_SYNC_ACRS;
- cs->kvm_run->kvm_dirty_regs |= KVM_SYNC_CRS;
- } else {
- for (i = 0; i < 16; i++) {
- sregs.acrs[i] = env->aregs[i];
- sregs.crs[i] = env->cregs[i];
- }
- r = kvm_vcpu_ioctl(cs, KVM_SET_SREGS, &sregs);
- if (r < 0) {
- return r;
- }
- }
-
if (can_sync_regs(cs, KVM_SYNC_GSCB)) {
memcpy(cs->kvm_run->s.regs.gscb, env->gscb, 32);
cs->kvm_run->kvm_dirty_regs |= KVM_SYNC_GSCB;
@@ -612,22 +594,15 @@ int kvm_arch_put_registers(CPUState *cs, int level)
cs->kvm_run->kvm_dirty_regs |= KVM_SYNC_DIAG318;
}
- /* Finally the prefix */
- if (can_sync_regs(cs, KVM_SYNC_PREFIX)) {
- cs->kvm_run->s.regs.prefix = env->psa;
- cs->kvm_run->kvm_dirty_regs |= KVM_SYNC_PREFIX;
- } else {
- /* prefix is only supported via sync regs */
- }
return 0;
}
int kvm_arch_get_registers(CPUState *cs)
{
+ const int required_syncs = KVM_SYNC_GPRS | KVM_SYNC_ACRS |
+ KVM_SYNC_CRS | KVM_SYNC_PREFIX;
S390CPU *cpu = S390_CPU(cs);
CPUS390XState *env = &cpu->env;
- struct kvm_sregs sregs;
- struct kvm_regs regs;
struct kvm_fpu fpu;
int i, r;
@@ -635,37 +610,16 @@ int kvm_arch_get_registers(CPUState *cs)
env->psw.addr = cs->kvm_run->psw_addr;
env->psw.mask = cs->kvm_run->psw_mask;
- /* the GPRS */
- if (can_sync_regs(cs, KVM_SYNC_GPRS)) {
- for (i = 0; i < 16; i++) {
- env->regs[i] = cs->kvm_run->s.regs.gprs[i];
- }
- } else {
- r = kvm_vcpu_ioctl(cs, KVM_GET_REGS, ®s);
- if (r < 0) {
- return r;
- }
- for (i = 0; i < 16; i++) {
- env->regs[i] = regs.gprs[i];
- }
+ /* the GPRS, ACRS and CRS */
+ g_assert((cs->kvm_run->kvm_valid_regs & required_syncs) == required_syncs);
+ for (i = 0; i < 16; i++) {
+ env->regs[i] = cs->kvm_run->s.regs.gprs[i];
+ env->aregs[i] = cs->kvm_run->s.regs.acrs[i];
+ env->cregs[i] = cs->kvm_run->s.regs.crs[i];
}
- /* The ACRS and CRS */
- if (can_sync_regs(cs, KVM_SYNC_ACRS | KVM_SYNC_CRS)) {
- for (i = 0; i < 16; i++) {
- env->aregs[i] = cs->kvm_run->s.regs.acrs[i];
- env->cregs[i] = cs->kvm_run->s.regs.crs[i];
- }
- } else {
- r = kvm_vcpu_ioctl(cs, KVM_GET_SREGS, &sregs);
- if (r < 0) {
- return r;
- }
- for (i = 0; i < 16; i++) {
- env->aregs[i] = sregs.acrs[i];
- env->cregs[i] = sregs.crs[i];
- }
- }
+ /* The prefix */
+ env->psa = cs->kvm_run->s.regs.prefix;
/* Floating point and vector registers */
if (can_sync_regs(cs, KVM_SYNC_VRS)) {
@@ -690,11 +644,6 @@ int kvm_arch_get_registers(CPUState *cs)
env->fpc = fpu.fpc;
}
- /* The prefix */
- if (can_sync_regs(cs, KVM_SYNC_PREFIX)) {
- env->psa = cs->kvm_run->s.regs.prefix;
- }
-
if (can_sync_regs(cs, KVM_SYNC_ARCH0)) {
env->cputm = cs->kvm_run->s.regs.cputm;
env->ckc = cs->kvm_run->s.regs.ckc;
