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// SPDX-License-Identifier: GPL-2.0-only
/*
* Host SVE: Check FPSIMD/SVE/SME save/restore over KVM_RUN ioctls.
*
* Copyright 2025 Arm, Ltd
*/
#include <errno.h>
#include <signal.h>
#include <sys/auxv.h>
#include <asm/kvm.h>
#include <kvm_util.h>
#include "ucall_common.h"
static void guest_code(void)
{
for (int i = 0; i < 10; i++) {
GUEST_UCALL_NONE();
}
GUEST_DONE();
}
void handle_sigill(int sig, siginfo_t *info, void *ctx)
{
ucontext_t *uctx = ctx;
printf(" < host signal %d >\n", sig);
/*
* Skip the UDF
*/
uctx->uc_mcontext.pc += 4;
}
void register_sigill_handler(void)
{
struct sigaction sa = {
.sa_sigaction = handle_sigill,
.sa_flags = SA_SIGINFO,
};
sigaction(SIGILL, &sa, NULL);
}
static void do_sve_roundtrip(void)
{
unsigned long before, after;
/*
* Set all bits in a predicate register, force a save/restore via a
* SIGILL (which handle_sigill() will recover from), then report
* whether the value has changed.
*/
asm volatile(
" .arch_extension sve\n"
" ptrue p0.B\n"
" cntp %[before], p0, p0.B\n"
" udf #0\n"
" cntp %[after], p0, p0.B\n"
: [before] "=r" (before),
[after] "=r" (after)
:
: "p0"
);
if (before != after) {
TEST_FAIL("Signal roundtrip discarded predicate bits (%ld => %ld)\n",
before, after);
} else {
printf("Signal roundtrip preserved predicate bits (%ld => %ld)\n",
before, after);
}
}
static void test_run(void)
{
struct kvm_vcpu *vcpu;
struct kvm_vm *vm;
struct ucall uc;
bool guest_done = false;
register_sigill_handler();
vm = vm_create_with_one_vcpu(&vcpu, guest_code);
do_sve_roundtrip();
while (!guest_done) {
printf("Running VCPU...\n");
vcpu_run(vcpu);
switch (get_ucall(vcpu, &uc)) {
case UCALL_NONE:
do_sve_roundtrip();
do_sve_roundtrip();
break;
case UCALL_DONE:
guest_done = true;
break;
case UCALL_ABORT:
REPORT_GUEST_ASSERT(uc);
break;
default:
TEST_FAIL("Unexpected guest exit");
}
}
kvm_vm_free(vm);
}
int main(void)
{
/*
* This is testing the host environment, we don't care about
* guest SVE support.
*/
if (!(getauxval(AT_HWCAP) & HWCAP_SVE)) {
printf("SVE not supported\n");
return KSFT_SKIP;
}
test_run();
return 0;
}
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