tools/testing/selftests/kvm/lib/ucall_common.c


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// SPDX-License-Identifier: GPL-2.0-only
#include "kvm_util.h"

void ucall(uint64_t cmd, int nargs, ...)
{
	struct ucall uc = {};
	va_list va;
	int i;

	WRITE_ONCE(uc.cmd, cmd);

	nargs = min(nargs, UCALL_MAX_ARGS);

	va_start(va, nargs);
	for (i = 0; i < nargs; ++i)
		WRITE_ONCE(uc.args[i], va_arg(va, uint64_t));
	va_end(va);

	ucall_arch_do_ucall((vm_vaddr_t)&uc);
}

uint64_t get_ucall(struct kvm_vcpu *vcpu, struct ucall *uc)
{
	struct ucall ucall;
	void *addr;

	if (!uc)
		uc = &ucall;

	addr = ucall_arch_get_ucall(vcpu);
	if (addr) {
		memcpy(uc, addr, sizeof(*uc));
		vcpu_run_complete_io(vcpu);
	} else {
		memset(uc, 0, sizeof(*uc));
	}

	return uc->cmd;
}