korg/linux
0
0
Fork 0
mirror of https://mirrors.bfsu.edu.cn/git/linux.git synced 2025-01-06 05:44:20 +08:00
Code Issues Packages Projects Releases Wiki Activity
fe4e771d5c
linux/arch/powerpc/kvm/booke.c
Hollis Blanchard d4cf3892e5 KVM: ppc: optimize irq delivery path 
In kvmppc_deliver_interrupt is just one case left in the switch and it is a
rare one (less than 8%) when looking at the exit numbers. Therefore we can
at least drop the switch/case and if an if. I inserted an unlikely too, but
that's open for discussion.

In kvmppc_can_deliver_interrupt all frequent cases are in the default case.
I know compilers are smart but we can make it easier for them. By writing
down all options and removing the default case combined with the fact that
ithe values are constants 0..15 should allow the compiler to write an easy
jump table.
Modifying kvmppc_can_deliver_interrupt pointed me to the fact that gcc seems
to be unable to reduce priority_exception[x] to a build time constant.
Therefore I changed the usage of the translation arrays in the interrupt
delivery path completely. It is now using priority without translation to irq
on the full irq delivery path.
To be able to do that ivpr regs are stored by their priority now.

Additionally the decision made in kvmppc_can_deliver_interrupt is already
sufficient to get the value of interrupt_msr_mask[x]. Therefore we can replace
the 16x4byte array used here with a single 4byte variable (might still be one
miss, but the chance to find this in cache should be better than the right
entry of the whole array).

Signed-off-by: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-12-31 16:52:23 +02:00

550 lines
15 KiB
C
Raw Blame History

/*
* 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. 2007
*
* Authors: Hollis Blanchard <hollisb@us.ibm.com>
* Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
*/
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/kvm_host.h>
#include <linux/module.h>
#include <linux/vmalloc.h>
#include <linux/fs.h>
#include <asm/cputable.h>
#include <asm/uaccess.h>
#include <asm/kvm_ppc.h>
#include <asm/cacheflush.h>
#include "booke.h"
#include "44x_tlb.h"
unsigned long kvmppc_booke_handlers;
#define VM_STAT(x) offsetof(struct kvm, stat.x), KVM_STAT_VM
#define VCPU_STAT(x) offsetof(struct kvm_vcpu, stat.x), KVM_STAT_VCPU
struct kvm_stats_debugfs_item debugfs_entries[] = {
{ "mmio", VCPU_STAT(mmio_exits) },
{ "dcr", VCPU_STAT(dcr_exits) },
{ "sig", VCPU_STAT(signal_exits) },
{ "itlb_r", VCPU_STAT(itlb_real_miss_exits) },
{ "itlb_v", VCPU_STAT(itlb_virt_miss_exits) },
{ "dtlb_r", VCPU_STAT(dtlb_real_miss_exits) },
{ "dtlb_v", VCPU_STAT(dtlb_virt_miss_exits) },
{ "sysc", VCPU_STAT(syscall_exits) },
{ "isi", VCPU_STAT(isi_exits) },
{ "dsi", VCPU_STAT(dsi_exits) },
{ "inst_emu", VCPU_STAT(emulated_inst_exits) },
{ "dec", VCPU_STAT(dec_exits) },
{ "ext_intr", VCPU_STAT(ext_intr_exits) },
{ "halt_wakeup", VCPU_STAT(halt_wakeup) },
{ NULL }
};
/* TODO: use vcpu_printf() */
void kvmppc_dump_vcpu(struct kvm_vcpu *vcpu)
{
int i;
printk("pc: %08lx msr: %08lx\n", vcpu->arch.pc, vcpu->arch.msr);
printk("lr: %08lx ctr: %08lx\n", vcpu->arch.lr, vcpu->arch.ctr);
printk("srr0: %08lx srr1: %08lx\n", vcpu->arch.srr0, vcpu->arch.srr1);
printk("exceptions: %08lx\n", vcpu->arch.pending_exceptions);
for (i = 0; i < 32; i += 4) {
printk("gpr%02d: %08lx %08lx %08lx %08lx\n", i,
vcpu->arch.gpr[i],
vcpu->arch.gpr[i+1],
vcpu->arch.gpr[i+2],
vcpu->arch.gpr[i+3]);
}
}
static void kvmppc_booke_queue_irqprio(struct kvm_vcpu *vcpu,
unsigned int priority)
{
set_bit(priority, &vcpu->arch.pending_exceptions);
}
void kvmppc_core_queue_program(struct kvm_vcpu *vcpu)
{
kvmppc_booke_queue_irqprio(vcpu, BOOKE_IRQPRIO_PROGRAM);
}
void kvmppc_core_queue_dec(struct kvm_vcpu *vcpu)
{
kvmppc_booke_queue_irqprio(vcpu, BOOKE_IRQPRIO_DECREMENTER);
}
int kvmppc_core_pending_dec(struct kvm_vcpu *vcpu)
{
return test_bit(BOOKE_IRQPRIO_DECREMENTER, &vcpu->arch.pending_exceptions);
}
void kvmppc_core_queue_external(struct kvm_vcpu *vcpu,
struct kvm_interrupt *irq)
{
kvmppc_booke_queue_irqprio(vcpu, BOOKE_IRQPRIO_EXTERNAL);
}
/* Deliver the interrupt of the corresponding priority, if possible. */
static int kvmppc_booke_irqprio_deliver(struct kvm_vcpu *vcpu,
unsigned int priority)
{
int allowed = 0;
ulong msr_mask;
switch (priority) {
case BOOKE_IRQPRIO_PROGRAM:
case BOOKE_IRQPRIO_DTLB_MISS:
case BOOKE_IRQPRIO_ITLB_MISS:
case BOOKE_IRQPRIO_SYSCALL:
case BOOKE_IRQPRIO_DATA_STORAGE:
case BOOKE_IRQPRIO_INST_STORAGE:
case BOOKE_IRQPRIO_FP_UNAVAIL:
case BOOKE_IRQPRIO_AP_UNAVAIL:
case BOOKE_IRQPRIO_ALIGNMENT:
allowed = 1;
msr_mask = MSR_CE|MSR_ME|MSR_DE;
break;
case BOOKE_IRQPRIO_CRITICAL:
case BOOKE_IRQPRIO_WATCHDOG:
allowed = vcpu->arch.msr & MSR_CE;
msr_mask = MSR_ME;
break;
case BOOKE_IRQPRIO_MACHINE_CHECK:
allowed = vcpu->arch.msr & MSR_ME;
msr_mask = 0;
break;
case BOOKE_IRQPRIO_EXTERNAL:
case BOOKE_IRQPRIO_DECREMENTER:
case BOOKE_IRQPRIO_FIT:
allowed = vcpu->arch.msr & MSR_EE;
msr_mask = MSR_CE|MSR_ME|MSR_DE;
break;
case BOOKE_IRQPRIO_DEBUG:
allowed = vcpu->arch.msr & MSR_DE;
msr_mask = MSR_ME;
break;
}
if (allowed) {
vcpu->arch.srr0 = vcpu->arch.pc;
vcpu->arch.srr1 = vcpu->arch.msr;
vcpu->arch.pc = vcpu->arch.ivpr | vcpu->arch.ivor[priority];
kvmppc_set_msr(vcpu, vcpu->arch.msr & msr_mask);
clear_bit(priority, &vcpu->arch.pending_exceptions);
}
return allowed;
}
/* Check pending exceptions and deliver one, if possible. */
void kvmppc_core_deliver_interrupts(struct kvm_vcpu *vcpu)
{
unsigned long *pending = &vcpu->arch.pending_exceptions;
unsigned int priority;
priority = __ffs(*pending);
while (priority <= BOOKE_MAX_INTERRUPT) {
if (kvmppc_booke_irqprio_deliver(vcpu, priority))
break;
priority = find_next_bit(pending,
BITS_PER_BYTE * sizeof(*pending),
priority + 1);
}
}
/**
* kvmppc_handle_exit
*
* Return value is in the form (errcode<<2 | RESUME_FLAG_HOST | RESUME_FLAG_NV)
*/
int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu,
unsigned int exit_nr)
{
enum emulation_result er;
int r = RESUME_HOST;
local_irq_enable();
run->exit_reason = KVM_EXIT_UNKNOWN;
run->ready_for_interrupt_injection = 1;
switch (exit_nr) {
case BOOKE_INTERRUPT_MACHINE_CHECK:
printk("MACHINE CHECK: %lx\n", mfspr(SPRN_MCSR));
kvmppc_dump_vcpu(vcpu);
r = RESUME_HOST;
break;
case BOOKE_INTERRUPT_EXTERNAL:
vcpu->stat.ext_intr_exits++;
if (need_resched())
cond_resched();
r = RESUME_GUEST;
break;
case BOOKE_INTERRUPT_DECREMENTER:
/* Since we switched IVPR back to the host's value, the host
* handled this interrupt the moment we enabled interrupts.
* Now we just offer it a chance to reschedule the guest. */
/* XXX At this point the TLB still holds our shadow TLB, so if
* we do reschedule the host will fault over it. Perhaps we
* should politely restore the host's entries to minimize
* misses before ceding control. */
vcpu->stat.dec_exits++;
if (need_resched())
cond_resched();
r = RESUME_GUEST;
break;
case BOOKE_INTERRUPT_PROGRAM:
if (vcpu->arch.msr & MSR_PR) {
/* Program traps generated by user-level software must be handled
* by the guest kernel. */
vcpu->arch.esr = vcpu->arch.fault_esr;
kvmppc_booke_queue_irqprio(vcpu, BOOKE_IRQPRIO_PROGRAM);
r = RESUME_GUEST;
break;
}
er = kvmppc_emulate_instruction(run, vcpu);
switch (er) {
case EMULATE_DONE:
/* Future optimization: only reload non-volatiles if
* they were actually modified by emulation. */
vcpu->stat.emulated_inst_exits++;
r = RESUME_GUEST_NV;
break;
case EMULATE_DO_DCR:
run->exit_reason = KVM_EXIT_DCR;
vcpu->stat.dcr_exits++;
r = RESUME_HOST;
break;
case EMULATE_FAIL:
/* XXX Deliver Program interrupt to guest. */
printk(KERN_CRIT "%s: emulation at %lx failed (%08x)\n",
__func__, vcpu->arch.pc, vcpu->arch.last_inst);
/* For debugging, encode the failing instruction and
* report it to userspace. */
run->hw.hardware_exit_reason = ~0ULL << 32;
run->hw.hardware_exit_reason |= vcpu->arch.last_inst;
r = RESUME_HOST;
break;
default:
BUG();
}
break;
case BOOKE_INTERRUPT_FP_UNAVAIL:
kvmppc_booke_queue_irqprio(vcpu, BOOKE_IRQPRIO_FP_UNAVAIL);
r = RESUME_GUEST;
break;
case BOOKE_INTERRUPT_DATA_STORAGE:
vcpu->arch.dear = vcpu->arch.fault_dear;
vcpu->arch.esr = vcpu->arch.fault_esr;
kvmppc_booke_queue_irqprio(vcpu, BOOKE_IRQPRIO_DATA_STORAGE);
vcpu->stat.dsi_exits++;
r = RESUME_GUEST;
break;
case BOOKE_INTERRUPT_INST_STORAGE:
vcpu->arch.esr = vcpu->arch.fault_esr;
kvmppc_booke_queue_irqprio(vcpu, BOOKE_IRQPRIO_INST_STORAGE);
vcpu->stat.isi_exits++;
r = RESUME_GUEST;
break;
case BOOKE_INTERRUPT_SYSCALL:
kvmppc_booke_queue_irqprio(vcpu, BOOKE_IRQPRIO_SYSCALL);
vcpu->stat.syscall_exits++;
r = RESUME_GUEST;
break;
case BOOKE_INTERRUPT_DTLB_MISS: {
struct kvmppc_44x_tlbe *gtlbe;
unsigned long eaddr = vcpu->arch.fault_dear;
gfn_t gfn;
/* Check the guest TLB. */
gtlbe = kvmppc_44x_dtlb_search(vcpu, eaddr);
if (!gtlbe) {
/* The guest didn't have a mapping for it. */
kvmppc_booke_queue_irqprio(vcpu, BOOKE_IRQPRIO_DTLB_MISS);
vcpu->arch.dear = vcpu->arch.fault_dear;
vcpu->arch.esr = vcpu->arch.fault_esr;
vcpu->stat.dtlb_real_miss_exits++;
r = RESUME_GUEST;
break;
}
vcpu->arch.paddr_accessed = tlb_xlate(gtlbe, eaddr);
gfn = vcpu->arch.paddr_accessed >> PAGE_SHIFT;
if (kvm_is_visible_gfn(vcpu->kvm, gfn)) {
/* The guest TLB had a mapping, but the shadow TLB
* didn't, and it is RAM. This could be because:
* a) the entry is mapping the host kernel, or
* b) the guest used a large mapping which we're faking
* Either way, we need to satisfy the fault without
* invoking the guest. */
kvmppc_mmu_map(vcpu, eaddr, gfn, gtlbe->tid,
gtlbe->word2);
vcpu->stat.dtlb_virt_miss_exits++;
r = RESUME_GUEST;
} else {
/* Guest has mapped and accessed a page which is not
* actually RAM. */
r = kvmppc_emulate_mmio(run, vcpu);
vcpu->stat.mmio_exits++;
}
break;
}
case BOOKE_INTERRUPT_ITLB_MISS: {
struct kvmppc_44x_tlbe *gtlbe;
unsigned long eaddr = vcpu->arch.pc;
gfn_t gfn;
r = RESUME_GUEST;
/* Check the guest TLB. */
gtlbe = kvmppc_44x_itlb_search(vcpu, eaddr);
if (!gtlbe) {
/* The guest didn't have a mapping for it. */
kvmppc_booke_queue_irqprio(vcpu, BOOKE_IRQPRIO_ITLB_MISS);
vcpu->stat.itlb_real_miss_exits++;
break;
}
vcpu->stat.itlb_virt_miss_exits++;
gfn = tlb_xlate(gtlbe, eaddr) >> PAGE_SHIFT;
if (kvm_is_visible_gfn(vcpu->kvm, gfn)) {
/* The guest TLB had a mapping, but the shadow TLB
* didn't. This could be because:
* a) the entry is mapping the host kernel, or
* b) the guest used a large mapping which we're faking
* Either way, we need to satisfy the fault without
* invoking the guest. */
kvmppc_mmu_map(vcpu, eaddr, gfn, gtlbe->tid,
gtlbe->word2);
} else {
/* Guest mapped and leaped at non-RAM! */
kvmppc_booke_queue_irqprio(vcpu, BOOKE_IRQPRIO_MACHINE_CHECK);
}
break;
}
case BOOKE_INTERRUPT_DEBUG: {
u32 dbsr;
vcpu->arch.pc = mfspr(SPRN_CSRR0);
/* clear IAC events in DBSR register */
dbsr = mfspr(SPRN_DBSR);
dbsr &= DBSR_IAC1 | DBSR_IAC2 | DBSR_IAC3 | DBSR_IAC4;
mtspr(SPRN_DBSR, dbsr);
run->exit_reason = KVM_EXIT_DEBUG;
r = RESUME_HOST;
break;
}
default:
printk(KERN_EMERG "exit_nr %d\n", exit_nr);
BUG();
}
local_irq_disable();
kvmppc_core_deliver_interrupts(vcpu);
if (!(r & RESUME_HOST)) {
/* To avoid clobbering exit_reason, only check for signals if
* we aren't already exiting to userspace for some other
* reason. */
if (signal_pending(current)) {
run->exit_reason = KVM_EXIT_INTR;
r = (-EINTR << 2) | RESUME_HOST | (r & RESUME_FLAG_NV);
vcpu->stat.signal_exits++;
}
}
return r;
}
/* Initial guest state: 16MB mapping 0 -> 0, PC = 0, MSR = 0, R1 = 16MB */
int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)
{
vcpu->arch.pc = 0;
vcpu->arch.msr = 0;
vcpu->arch.gpr[1] = (16<<20) - 8; /* -8 for the callee-save LR slot */
vcpu->arch.shadow_pid = 1;
/* Eye-catching number so we know if the guest takes an interrupt
* before it's programmed its own IVPR. */
vcpu->arch.ivpr = 0x55550000;
return kvmppc_core_vcpu_setup(vcpu);
}
int kvm_arch_vcpu_ioctl_get_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
{
int i;
regs->pc = vcpu->arch.pc;
regs->cr = vcpu->arch.cr;
regs->ctr = vcpu->arch.ctr;
regs->lr = vcpu->arch.lr;
regs->xer = vcpu->arch.xer;
regs->msr = vcpu->arch.msr;
regs->srr0 = vcpu->arch.srr0;
regs->srr1 = vcpu->arch.srr1;
regs->pid = vcpu->arch.pid;
regs->sprg0 = vcpu->arch.sprg0;
regs->sprg1 = vcpu->arch.sprg1;
regs->sprg2 = vcpu->arch.sprg2;
regs->sprg3 = vcpu->arch.sprg3;
regs->sprg5 = vcpu->arch.sprg4;
regs->sprg6 = vcpu->arch.sprg5;
regs->sprg7 = vcpu->arch.sprg6;
for (i = 0; i < ARRAY_SIZE(regs->gpr); i++)
regs->gpr[i] = vcpu->arch.gpr[i];
return 0;
}
int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
{
int i;
vcpu->arch.pc = regs->pc;
vcpu->arch.cr = regs->cr;
vcpu->arch.ctr = regs->ctr;
vcpu->arch.lr = regs->lr;
vcpu->arch.xer = regs->xer;
kvmppc_set_msr(vcpu, regs->msr);
vcpu->arch.srr0 = regs->srr0;
vcpu->arch.srr1 = regs->srr1;
vcpu->arch.sprg0 = regs->sprg0;
vcpu->arch.sprg1 = regs->sprg1;
vcpu->arch.sprg2 = regs->sprg2;
vcpu->arch.sprg3 = regs->sprg3;
vcpu->arch.sprg5 = regs->sprg4;
vcpu->arch.sprg6 = regs->sprg5;
vcpu->arch.sprg7 = regs->sprg6;
for (i = 0; i < ARRAY_SIZE(vcpu->arch.gpr); i++)
vcpu->arch.gpr[i] = regs->gpr[i];
return 0;
}
int kvm_arch_vcpu_ioctl_get_sregs(struct kvm_vcpu *vcpu,
struct kvm_sregs *sregs)
{
return -ENOTSUPP;
}
int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
struct kvm_sregs *sregs)
{
return -ENOTSUPP;
}
int kvm_arch_vcpu_ioctl_get_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
{
return -ENOTSUPP;
}
int kvm_arch_vcpu_ioctl_set_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
{
return -ENOTSUPP;
}
int kvm_arch_vcpu_ioctl_translate(struct kvm_vcpu *vcpu,
struct kvm_translation *tr)
{
return kvmppc_core_vcpu_translate(vcpu, tr);
}
int kvmppc_booke_init(void)
{
unsigned long ivor[16];
unsigned long max_ivor = 0;
int i;
/* We install our own exception handlers by hijacking IVPR. IVPR must
* be 16-bit aligned, so we need a 64KB allocation. */
kvmppc_booke_handlers = __get_free_pages(GFP_KERNEL | __GFP_ZERO,
VCPU_SIZE_ORDER);
if (!kvmppc_booke_handlers)
return -ENOMEM;
/* XXX make sure our handlers are smaller than Linux's */
/* Copy our interrupt handlers to match host IVORs. That way we don't
* have to swap the IVORs on every guest/host transition. */
ivor[0] = mfspr(SPRN_IVOR0);
ivor[1] = mfspr(SPRN_IVOR1);
ivor[2] = mfspr(SPRN_IVOR2);
ivor[3] = mfspr(SPRN_IVOR3);
ivor[4] = mfspr(SPRN_IVOR4);
ivor[5] = mfspr(SPRN_IVOR5);
ivor[6] = mfspr(SPRN_IVOR6);
ivor[7] = mfspr(SPRN_IVOR7);
ivor[8] = mfspr(SPRN_IVOR8);
ivor[9] = mfspr(SPRN_IVOR9);
ivor[10] = mfspr(SPRN_IVOR10);
ivor[11] = mfspr(SPRN_IVOR11);
ivor[12] = mfspr(SPRN_IVOR12);
ivor[13] = mfspr(SPRN_IVOR13);
ivor[14] = mfspr(SPRN_IVOR14);
ivor[15] = mfspr(SPRN_IVOR15);
for (i = 0; i < 16; i++) {
if (ivor[i] > max_ivor)
max_ivor = ivor[i];
memcpy((void *)kvmppc_booke_handlers + ivor[i],
kvmppc_handlers_start + i * kvmppc_handler_len,
kvmppc_handler_len);
}
flush_icache_range(kvmppc_booke_handlers,
kvmppc_booke_handlers + max_ivor + kvmppc_handler_len);
return 0;
}
void __exit kvmppc_booke_exit(void)
{
free_pages(kvmppc_booke_handlers, VCPU_SIZE_ORDER);
kvm_exit();
}
Reference in New Issue View Git Blame Copy Permalink