linux/arch/powerpc/kvm/44x.c
Hollis Blanchard c5fbdffbda KVM: ppc: save and restore guest mappings on context switch
Store shadow TLB entries in memory, but only use it on host context switch
(instead of every guest entry). This improves performance for most workloads on
440 by reducing the guest TLB miss rate.

Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-12-31 16:55:09 +02:00

228 lines
5.4 KiB
C

/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License, version 2, as
* published by the Free Software Foundation.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* Copyright IBM Corp. 2008
*
* Authors: Hollis Blanchard <hollisb@us.ibm.com>
*/
#include <linux/kvm_host.h>
#include <linux/err.h>
#include <asm/reg.h>
#include <asm/cputable.h>
#include <asm/tlbflush.h>
#include <asm/kvm_44x.h>
#include <asm/kvm_ppc.h>
#include "44x_tlb.h"
/* Note: clearing MSR[DE] just means that the debug interrupt will not be
* delivered *immediately*. Instead, it simply sets the appropriate DBSR bits.
* If those DBSR bits are still set when MSR[DE] is re-enabled, the interrupt
* will be delivered as an "imprecise debug event" (which is indicated by
* DBSR[IDE].
*/
static void kvm44x_disable_debug_interrupts(void)
{
mtmsr(mfmsr() & ~MSR_DE);
}
void kvmppc_core_load_host_debugstate(struct kvm_vcpu *vcpu)
{
kvm44x_disable_debug_interrupts();
mtspr(SPRN_IAC1, vcpu->arch.host_iac[0]);
mtspr(SPRN_IAC2, vcpu->arch.host_iac[1]);
mtspr(SPRN_IAC3, vcpu->arch.host_iac[2]);
mtspr(SPRN_IAC4, vcpu->arch.host_iac[3]);
mtspr(SPRN_DBCR1, vcpu->arch.host_dbcr1);
mtspr(SPRN_DBCR2, vcpu->arch.host_dbcr2);
mtspr(SPRN_DBCR0, vcpu->arch.host_dbcr0);
mtmsr(vcpu->arch.host_msr);
}
void kvmppc_core_load_guest_debugstate(struct kvm_vcpu *vcpu)
{
struct kvm_guest_debug *dbg = &vcpu->guest_debug;
u32 dbcr0 = 0;
vcpu->arch.host_msr = mfmsr();
kvm44x_disable_debug_interrupts();
/* Save host debug register state. */
vcpu->arch.host_iac[0] = mfspr(SPRN_IAC1);
vcpu->arch.host_iac[1] = mfspr(SPRN_IAC2);
vcpu->arch.host_iac[2] = mfspr(SPRN_IAC3);
vcpu->arch.host_iac[3] = mfspr(SPRN_IAC4);
vcpu->arch.host_dbcr0 = mfspr(SPRN_DBCR0);
vcpu->arch.host_dbcr1 = mfspr(SPRN_DBCR1);
vcpu->arch.host_dbcr2 = mfspr(SPRN_DBCR2);
/* set registers up for guest */
if (dbg->bp[0]) {
mtspr(SPRN_IAC1, dbg->bp[0]);
dbcr0 |= DBCR0_IAC1 | DBCR0_IDM;
}
if (dbg->bp[1]) {
mtspr(SPRN_IAC2, dbg->bp[1]);
dbcr0 |= DBCR0_IAC2 | DBCR0_IDM;
}
if (dbg->bp[2]) {
mtspr(SPRN_IAC3, dbg->bp[2]);
dbcr0 |= DBCR0_IAC3 | DBCR0_IDM;
}
if (dbg->bp[3]) {
mtspr(SPRN_IAC4, dbg->bp[3]);
dbcr0 |= DBCR0_IAC4 | DBCR0_IDM;
}
mtspr(SPRN_DBCR0, dbcr0);
mtspr(SPRN_DBCR1, 0);
mtspr(SPRN_DBCR2, 0);
}
void kvmppc_core_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
{
kvmppc_44x_tlb_load(vcpu);
}
void kvmppc_core_vcpu_put(struct kvm_vcpu *vcpu)
{
kvmppc_44x_tlb_put(vcpu);
}
int kvmppc_core_check_processor_compat(void)
{
int r;
if (strcmp(cur_cpu_spec->platform, "ppc440") == 0)
r = 0;
else
r = -ENOTSUPP;
return r;
}
int kvmppc_core_vcpu_setup(struct kvm_vcpu *vcpu)
{
struct kvmppc_vcpu_44x *vcpu_44x = to_44x(vcpu);
struct kvmppc_44x_tlbe *tlbe = &vcpu_44x->guest_tlb[0];
int i;
tlbe->tid = 0;
tlbe->word0 = PPC44x_TLB_16M | PPC44x_TLB_VALID;
tlbe->word1 = 0;
tlbe->word2 = PPC44x_TLB_SX | PPC44x_TLB_SW | PPC44x_TLB_SR;
tlbe++;
tlbe->tid = 0;
tlbe->word0 = 0xef600000 | PPC44x_TLB_4K | PPC44x_TLB_VALID;
tlbe->word1 = 0xef600000;
tlbe->word2 = PPC44x_TLB_SX | PPC44x_TLB_SW | PPC44x_TLB_SR
| PPC44x_TLB_I | PPC44x_TLB_G;
/* Since the guest can directly access the timebase, it must know the
* real timebase frequency. Accordingly, it must see the state of
* CCR1[TCS]. */
vcpu->arch.ccr1 = mfspr(SPRN_CCR1);
for (i = 0; i < ARRAY_SIZE(vcpu_44x->shadow_refs); i++)
vcpu_44x->shadow_refs[i].gtlb_index = -1;
return 0;
}
/* 'linear_address' is actually an encoding of AS|PID|EADDR . */
int kvmppc_core_vcpu_translate(struct kvm_vcpu *vcpu,
struct kvm_translation *tr)
{
struct kvmppc_vcpu_44x *vcpu_44x = to_44x(vcpu);
struct kvmppc_44x_tlbe *gtlbe;
int index;
gva_t eaddr;
u8 pid;
u8 as;
eaddr = tr->linear_address;
pid = (tr->linear_address >> 32) & 0xff;
as = (tr->linear_address >> 40) & 0x1;
index = kvmppc_44x_tlb_index(vcpu, eaddr, pid, as);
if (index == -1) {
tr->valid = 0;
return 0;
}
gtlbe = &vcpu_44x->guest_tlb[index];
tr->physical_address = tlb_xlate(gtlbe, eaddr);
/* XXX what does "writeable" and "usermode" even mean? */
tr->valid = 1;
return 0;
}
struct kvm_vcpu *kvmppc_core_vcpu_create(struct kvm *kvm, unsigned int id)
{
struct kvmppc_vcpu_44x *vcpu_44x;
struct kvm_vcpu *vcpu;
int err;
vcpu_44x = kmem_cache_zalloc(kvm_vcpu_cache, GFP_KERNEL);
if (!vcpu_44x) {
err = -ENOMEM;
goto out;
}
vcpu = &vcpu_44x->vcpu;
err = kvm_vcpu_init(vcpu, kvm, id);
if (err)
goto free_vcpu;
return vcpu;
free_vcpu:
kmem_cache_free(kvm_vcpu_cache, vcpu_44x);
out:
return ERR_PTR(err);
}
void kvmppc_core_vcpu_free(struct kvm_vcpu *vcpu)
{
struct kvmppc_vcpu_44x *vcpu_44x = to_44x(vcpu);
kvm_vcpu_uninit(vcpu);
kmem_cache_free(kvm_vcpu_cache, vcpu_44x);
}
static int kvmppc_44x_init(void)
{
int r;
r = kvmppc_booke_init();
if (r)
return r;
return kvm_init(NULL, sizeof(struct kvmppc_vcpu_44x), THIS_MODULE);
}
static void kvmppc_44x_exit(void)
{
kvmppc_booke_exit();
}
module_init(kvmppc_44x_init);
module_exit(kvmppc_44x_exit);