Skip to content

Commit

Permalink
target/s390x/kvm: Simplify the GPRs, ACRs, CRs and prefix synchroniza…
Browse files Browse the repository at this point in the history 
…tion code

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 also 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.

Message-ID: <20231011080538.796999-3-thuth@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
  • Loading branch information
@huth
huth committed Oct 20, 2023
1 parent c35a79c commit 1d10716
Showing 1 changed file with 24 additions and 82 deletions.
106 changes: 24 additions & 82 deletions target/s390x/kvm/kvm.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -139,7 +139,6 @@ 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;
Expand Down Expand Up @@ -360,7 +359,6 @@ int kvm_arch_init(MachineState *ms, KVMState *s)
return -1;
}

cap_sync_regs = true;
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);
Expand Down Expand Up @@ -468,37 +466,28 @@ 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;
}

#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)
{
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;

g_assert(can_sync_regs(cs, KVM_SYNC_REQUIRED_REGS));

/* always save the PSW and the GPRS*/
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, &regs);
if (r < 0) {
return r;
}
}
memcpy(cs->kvm_run->s.regs.gprs, env->regs, sizeof(cs->kvm_run->s.regs.gprs));
cs->kvm_run->kvm_dirty_regs |= KVM_SYNC_GPRS;

if (can_sync_regs(cs, KVM_SYNC_VRS)) {
for (i = 0; i < 32; i++) {
Expand Down Expand Up @@ -531,6 +520,15 @@ int kvm_arch_put_registers(CPUState *cs, int level)
return 0;
}

/*
* Access registers, control registers and the prefix - these are
* always available via kvm_sync_regs in the kernels that we support
*/
memcpy(cs->kvm_run->s.regs.acrs, env->aregs, sizeof(cs->kvm_run->s.regs.acrs));
memcpy(cs->kvm_run->s.regs.crs, env->cregs, sizeof(cs->kvm_run->s.regs.crs));
cs->kvm_run->s.regs.prefix = env->psa;
cs->kvm_run->kvm_dirty_regs |= KVM_SYNC_ACRS | KVM_SYNC_CRS | KVM_SYNC_PREFIX;

if (can_sync_regs(cs, KVM_SYNC_ARCH0)) {
cs->kvm_run->s.regs.cputm = env->cputm;
cs->kvm_run->s.regs.ckc = env->ckc;
Expand Down Expand Up @@ -577,25 +575,6 @@ 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;
Expand All @@ -617,60 +596,28 @@ 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)
{
S390CPU *cpu = S390_CPU(cs);
CPUS390XState *env = &cpu->env;
struct kvm_sregs sregs;
struct kvm_regs regs;
struct kvm_fpu fpu;
int i, r;

/* get the PSW */
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, &regs);
if (r < 0) {
return r;
}
for (i = 0; i < 16; i++) {
env->regs[i] = regs.gprs[i];
}
}
/* the GPRS, ACRS and CRS */
g_assert(can_sync_regs(cs, KVM_SYNC_REQUIRED_REGS));
memcpy(env->regs, cs->kvm_run->s.regs.gprs, sizeof(env->regs));
memcpy(env->aregs, cs->kvm_run->s.regs.acrs, sizeof(env->aregs));
memcpy(env->cregs, cs->kvm_run->s.regs.crs, sizeof(env->cregs));

/* 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)) {
Expand All @@ -695,11 +642,6 @@ 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;
Expand Down

0 comments on commit 1d10716

Please sign in to comment.