60 lines
1.2 KiB
C
60 lines
1.2 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* ucall support. A ucall is a "hypercall to userspace".
|
|
*
|
|
* Copyright (C) 2018, Red Hat, Inc.
|
|
*/
|
|
#include "kvm_util.h"
|
|
|
|
#define UCALL_PIO_PORT ((uint16_t)0x1000)
|
|
|
|
void ucall_init(struct kvm_vm *vm, void *arg)
|
|
{
|
|
}
|
|
|
|
void ucall_uninit(struct kvm_vm *vm)
|
|
{
|
|
}
|
|
|
|
void ucall(uint64_t cmd, int nargs, ...)
|
|
{
|
|
struct ucall uc = {
|
|
.cmd = cmd,
|
|
};
|
|
va_list va;
|
|
int i;
|
|
|
|
nargs = nargs <= UCALL_MAX_ARGS ? nargs : UCALL_MAX_ARGS;
|
|
|
|
va_start(va, nargs);
|
|
for (i = 0; i < nargs; ++i)
|
|
uc.args[i] = va_arg(va, uint64_t);
|
|
va_end(va);
|
|
|
|
asm volatile("in %[port], %%al"
|
|
: : [port] "d" (UCALL_PIO_PORT), "D" (&uc) : "rax", "memory");
|
|
}
|
|
|
|
uint64_t get_ucall(struct kvm_vm *vm, uint32_t vcpu_id, struct ucall *uc)
|
|
{
|
|
struct kvm_run *run = vcpu_state(vm, vcpu_id);
|
|
struct ucall ucall = {};
|
|
|
|
if (uc)
|
|
memset(uc, 0, sizeof(*uc));
|
|
|
|
if (run->exit_reason == KVM_EXIT_IO && run->io.port == UCALL_PIO_PORT) {
|
|
struct kvm_regs regs;
|
|
|
|
vcpu_regs_get(vm, vcpu_id, ®s);
|
|
memcpy(&ucall, addr_gva2hva(vm, (vm_vaddr_t)regs.rdi),
|
|
sizeof(ucall));
|
|
|
|
vcpu_run_complete_io(vm, vcpu_id);
|
|
if (uc)
|
|
memcpy(uc, &ucall, sizeof(ucall));
|
|
}
|
|
|
|
return ucall.cmd;
|
|
}
|