linux/arch/mips/kvm/tlb.c

216 lines
5.4 KiB
C

/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* KVM/MIPS TLB handling, this file is part of the Linux host kernel so that
* TLB handlers run from KSEG0
*
* Copyright (C) 2012 MIPS Technologies, Inc. All rights reserved.
* Authors: Sanjay Lal <sanjayl@kymasys.com>
*/
#include <linux/sched.h>
#include <linux/smp.h>
#include <linux/mm.h>
#include <linux/delay.h>
#include <linux/export.h>
#include <linux/kvm_host.h>
#include <linux/srcu.h>
#include <asm/cpu.h>
#include <asm/bootinfo.h>
#include <asm/mmu_context.h>
#include <asm/pgtable.h>
#include <asm/cacheflush.h>
#include <asm/tlb.h>
#include <asm/tlbdebug.h>
#undef CONFIG_MIPS_MT
#include <asm/r4kcache.h>
#define CONFIG_MIPS_MT
#define KVM_GUEST_PC_TLB 0
#define KVM_GUEST_SP_TLB 1
static u32 kvm_mips_get_kernel_asid(struct kvm_vcpu *vcpu)
{
struct mm_struct *kern_mm = &vcpu->arch.guest_kernel_mm;
int cpu = smp_processor_id();
return cpu_asid(cpu, kern_mm);
}
static u32 kvm_mips_get_user_asid(struct kvm_vcpu *vcpu)
{
struct mm_struct *user_mm = &vcpu->arch.guest_user_mm;
int cpu = smp_processor_id();
return cpu_asid(cpu, user_mm);
}
/* Structure defining an tlb entry data set. */
void kvm_mips_dump_host_tlbs(void)
{
unsigned long flags;
local_irq_save(flags);
kvm_info("HOST TLBs:\n");
dump_tlb_regs();
pr_info("\n");
dump_tlb_all();
local_irq_restore(flags);
}
EXPORT_SYMBOL_GPL(kvm_mips_dump_host_tlbs);
void kvm_mips_dump_guest_tlbs(struct kvm_vcpu *vcpu)
{
struct mips_coproc *cop0 = vcpu->arch.cop0;
struct kvm_mips_tlb tlb;
int i;
kvm_info("Guest TLBs:\n");
kvm_info("Guest EntryHi: %#lx\n", kvm_read_c0_guest_entryhi(cop0));
for (i = 0; i < KVM_MIPS_GUEST_TLB_SIZE; i++) {
tlb = vcpu->arch.guest_tlb[i];
kvm_info("TLB%c%3d Hi 0x%08lx ",
(tlb.tlb_lo[0] | tlb.tlb_lo[1]) & ENTRYLO_V
? ' ' : '*',
i, tlb.tlb_hi);
kvm_info("Lo0=0x%09llx %c%c attr %lx ",
(u64) mips3_tlbpfn_to_paddr(tlb.tlb_lo[0]),
(tlb.tlb_lo[0] & ENTRYLO_D) ? 'D' : ' ',
(tlb.tlb_lo[0] & ENTRYLO_G) ? 'G' : ' ',
(tlb.tlb_lo[0] & ENTRYLO_C) >> ENTRYLO_C_SHIFT);
kvm_info("Lo1=0x%09llx %c%c attr %lx sz=%lx\n",
(u64) mips3_tlbpfn_to_paddr(tlb.tlb_lo[1]),
(tlb.tlb_lo[1] & ENTRYLO_D) ? 'D' : ' ',
(tlb.tlb_lo[1] & ENTRYLO_G) ? 'G' : ' ',
(tlb.tlb_lo[1] & ENTRYLO_C) >> ENTRYLO_C_SHIFT,
tlb.tlb_mask);
}
}
EXPORT_SYMBOL_GPL(kvm_mips_dump_guest_tlbs);
int kvm_mips_guest_tlb_lookup(struct kvm_vcpu *vcpu, unsigned long entryhi)
{
int i;
int index = -1;
struct kvm_mips_tlb *tlb = vcpu->arch.guest_tlb;
for (i = 0; i < KVM_MIPS_GUEST_TLB_SIZE; i++) {
if (TLB_HI_VPN2_HIT(tlb[i], entryhi) &&
TLB_HI_ASID_HIT(tlb[i], entryhi)) {
index = i;
break;
}
}
kvm_debug("%s: entryhi: %#lx, index: %d lo0: %#lx, lo1: %#lx\n",
__func__, entryhi, index, tlb[i].tlb_lo[0], tlb[i].tlb_lo[1]);
return index;
}
EXPORT_SYMBOL_GPL(kvm_mips_guest_tlb_lookup);
static int _kvm_mips_host_tlb_inv(unsigned long entryhi)
{
int idx;
write_c0_entryhi(entryhi);
mtc0_tlbw_hazard();
tlb_probe();
tlb_probe_hazard();
idx = read_c0_index();
if (idx >= current_cpu_data.tlbsize)
BUG();
if (idx >= 0) {
write_c0_entryhi(UNIQUE_ENTRYHI(idx));
write_c0_entrylo0(0);
write_c0_entrylo1(0);
mtc0_tlbw_hazard();
tlb_write_indexed();
tlbw_use_hazard();
}
return idx;
}
int kvm_mips_host_tlb_inv(struct kvm_vcpu *vcpu, unsigned long va,
bool user, bool kernel)
{
int idx_user, idx_kernel;
unsigned long flags, old_entryhi;
local_irq_save(flags);
old_entryhi = read_c0_entryhi();
if (user)
idx_user = _kvm_mips_host_tlb_inv((va & VPN2_MASK) |
kvm_mips_get_user_asid(vcpu));
if (kernel)
idx_kernel = _kvm_mips_host_tlb_inv((va & VPN2_MASK) |
kvm_mips_get_kernel_asid(vcpu));
write_c0_entryhi(old_entryhi);
mtc0_tlbw_hazard();
local_irq_restore(flags);
if (user && idx_user >= 0)
kvm_debug("%s: Invalidated guest user entryhi %#lx @ idx %d\n",
__func__, (va & VPN2_MASK) |
kvm_mips_get_user_asid(vcpu), idx_user);
if (kernel && idx_kernel >= 0)
kvm_debug("%s: Invalidated guest kernel entryhi %#lx @ idx %d\n",
__func__, (va & VPN2_MASK) |
kvm_mips_get_kernel_asid(vcpu), idx_kernel);
return 0;
}
EXPORT_SYMBOL_GPL(kvm_mips_host_tlb_inv);
/**
* kvm_mips_suspend_mm() - Suspend the active mm.
* @cpu The CPU we're running on.
*
* Suspend the active_mm, ready for a switch to a KVM guest virtual address
* space. This is left active for the duration of guest context, including time
* with interrupts enabled, so we need to be careful not to confuse e.g. cache
* management IPIs.
*
* kvm_mips_resume_mm() should be called before context switching to a different
* process so we don't need to worry about reference counting.
*
* This needs to be in static kernel code to avoid exporting init_mm.
*/
void kvm_mips_suspend_mm(int cpu)
{
cpumask_clear_cpu(cpu, mm_cpumask(current->active_mm));
current->active_mm = &init_mm;
}
EXPORT_SYMBOL_GPL(kvm_mips_suspend_mm);
/**
* kvm_mips_resume_mm() - Resume the current process mm.
* @cpu The CPU we're running on.
*
* Resume the mm of the current process, after a switch back from a KVM guest
* virtual address space (see kvm_mips_suspend_mm()).
*/
void kvm_mips_resume_mm(int cpu)
{
cpumask_set_cpu(cpu, mm_cpumask(current->mm));
current->active_mm = current->mm;
}
EXPORT_SYMBOL_GPL(kvm_mips_resume_mm);