qemu/hw/mips/addr.c
James Hogan d3d93c6c1e mips: Add KVM T&E segment support for TCG
MIPS KVM trap & emulate guest kernels have a different segment layout
compared with traditional MIPS kernels, to allow both the user and
kernel code to run from the user address segment without repeatedly
trapping to KVM.

QEMU currently supports this layout only for KVM, but its sometimes
useful to be able to run these kernels in QEMU on a PC, so enable it for
TCG too.

This also paves the way for MIPS KVM VZ support (which uses the normal
virtual memory layout) by abstracting whether user mode kernel segments
are in use.

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Yongbok Kim <yongbok.kim@imgtec.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: kvm@vger.kernel.org
Reviewed-by: Richard Henderson <rth@twiddle.net>
[Yongbok Kim:
  minor change]
Signed-off-by: Yongbok Kim <yongbok.kim@imgtec.com>
2017-08-02 22:18:06 +01:00

53 lines
1.6 KiB
C

/*
* QEMU MIPS address translation support
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "qemu/osdep.h"
#include "hw/hw.h"
#include "hw/mips/cpudevs.h"
static int mips_um_ksegs;
uint64_t cpu_mips_kseg0_to_phys(void *opaque, uint64_t addr)
{
return addr & 0x1fffffffll;
}
uint64_t cpu_mips_phys_to_kseg0(void *opaque, uint64_t addr)
{
return addr | ~0x7fffffffll;
}
uint64_t cpu_mips_kvm_um_phys_to_kseg0(void *opaque, uint64_t addr)
{
return addr | 0x40000000ll;
}
bool mips_um_ksegs_enabled(void)
{
return mips_um_ksegs;
}
void mips_um_ksegs_enable(void)
{
mips_um_ksegs = 1;
}