qemu-patch-raspberry4/target-s390x/helper.c
Paul Brook d4c430a80f Large page TLB flush
QEMU uses a fixed page size for the CPU TLB.  If the guest uses large
pages then we effectively split these into multiple smaller pages, and
populate the corresponding TLB entries on demand.

When the guest invalidates the TLB by virtual address we must invalidate
all entries covered by the large page.  However the address used to
invalidate the entry may not be present in the QEMU TLB, so we do not
know which regions to clear.

Implementing a full vaiable size TLB is hard and slow, so just keep a
simple address/mask pair to record which addresses may have been mapped by
large pages.  If the guest invalidates this region then flush the
whole TLB.

Signed-off-by: Paul Brook <paul@codesourcery.com>
2010-03-17 02:44:41 +00:00

80 lines
2 KiB
C

/*
* S/390 helpers
*
* Copyright (c) 2009 Ulrich Hecht
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "cpu.h"
#include "exec-all.h"
#include "gdbstub.h"
#include "qemu-common.h"
#include <linux/kvm.h>
#include "kvm.h"
CPUS390XState *cpu_s390x_init(const char *cpu_model)
{
CPUS390XState *env;
static int inited = 0;
env = qemu_mallocz(sizeof(CPUS390XState));
cpu_exec_init(env);
if (!inited) {
inited = 1;
}
env->cpu_model_str = cpu_model;
cpu_reset(env);
qemu_init_vcpu(env);
return env;
}
void cpu_reset(CPUS390XState *env)
{
if (qemu_loglevel_mask(CPU_LOG_RESET)) {
qemu_log("CPU Reset (CPU %d)\n", env->cpu_index);
log_cpu_state(env, 0);
}
memset(env, 0, offsetof(CPUS390XState, breakpoints));
/* FIXME: reset vector? */
tlb_flush(env, 1);
}
#ifndef CONFIG_USER_ONLY
int cpu_s390x_handle_mmu_fault (CPUState *env, target_ulong address, int rw,
int mmu_idx, int is_softmmu)
{
target_ulong phys;
int prot;
/* XXX: implement mmu */
phys = address;
prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
tlb_set_page(env, address & TARGET_PAGE_MASK,
phys & TARGET_PAGE_MASK, prot,
mmu_idx, TARGET_PAGE_SIZE);
return 0;
}
#endif /* CONFIG_USER_ONLY */