linux/arch/mips/kvm/tlb.c

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/*
* 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
atomic_t kvm_mips_instance;
EXPORT_SYMBOL_GPL(kvm_mips_instance);
static u32 kvm_mips_get_kernel_asid(struct kvm_vcpu *vcpu)
{
int cpu = smp_processor_id();
return vcpu->arch.guest_kernel_asid[cpu] &
cpu_asid_mask(&cpu_data[cpu]);
}
static u32 kvm_mips_get_user_asid(struct kvm_vcpu *vcpu)
{
int cpu = smp_processor_id();
return vcpu->arch.guest_user_asid[cpu] &
cpu_asid_mask(&cpu_data[cpu]);
}
inline u32 kvm_mips_get_commpage_asid(struct kvm_vcpu *vcpu)
{
return vcpu->kvm->arch.commpage_tlb;
}
/* 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_lo0 | tlb.tlb_lo1) & MIPS3_PG_V ? ' ' : '*',
i, tlb.tlb_hi);
kvm_info("Lo0=0x%09llx %c%c attr %lx ",
(u64) mips3_tlbpfn_to_paddr(tlb.tlb_lo0),
(tlb.tlb_lo0 & MIPS3_PG_D) ? 'D' : ' ',
(tlb.tlb_lo0 & MIPS3_PG_G) ? 'G' : ' ',
(tlb.tlb_lo0 >> 3) & 7);
kvm_info("Lo1=0x%09llx %c%c attr %lx sz=%lx\n",
(u64) mips3_tlbpfn_to_paddr(tlb.tlb_lo1),
(tlb.tlb_lo1 & MIPS3_PG_D) ? 'D' : ' ',
(tlb.tlb_lo1 & MIPS3_PG_G) ? 'G' : ' ',
(tlb.tlb_lo1 >> 3) & 7, tlb.tlb_mask);
}
}
EXPORT_SYMBOL_GPL(kvm_mips_dump_guest_tlbs);
/* XXXKYMA: Must be called with interrupts disabled */
/* set flush_dcache_mask == 0 if no dcache flush required */
int kvm_mips_host_tlb_write(struct kvm_vcpu *vcpu, unsigned long entryhi,
unsigned long entrylo0, unsigned long entrylo1,
int flush_dcache_mask)
{
unsigned long flags;
unsigned long old_entryhi;
int idx;
local_irq_save(flags);
old_entryhi = read_c0_entryhi();
write_c0_entryhi(entryhi);
mtc0_tlbw_hazard();
tlb_probe();
tlb_probe_hazard();
idx = read_c0_index();
if (idx > current_cpu_data.tlbsize) {
kvm_err("%s: Invalid Index: %d\n", __func__, idx);
kvm_mips_dump_host_tlbs();
local_irq_restore(flags);
return -1;
}
write_c0_entrylo0(entrylo0);
write_c0_entrylo1(entrylo1);
mtc0_tlbw_hazard();
if (idx < 0)
tlb_write_random();
else
tlb_write_indexed();
tlbw_use_hazard();
kvm_debug("@ %#lx idx: %2d [entryhi(R): %#lx] entrylo0(R): 0x%08lx, entrylo1(R): 0x%08lx\n",
vcpu->arch.pc, idx, read_c0_entryhi(),
read_c0_entrylo0(), read_c0_entrylo1());
/* Flush D-cache */
if (flush_dcache_mask) {
if (entrylo0 & MIPS3_PG_V) {
++vcpu->stat.flush_dcache_exits;
flush_data_cache_page((entryhi & VPN2_MASK) &
~flush_dcache_mask);
}
if (entrylo1 & MIPS3_PG_V) {
++vcpu->stat.flush_dcache_exits;
flush_data_cache_page(((entryhi & VPN2_MASK) &
~flush_dcache_mask) |
(0x1 << PAGE_SHIFT));
}
}
/* Restore old ASID */
write_c0_entryhi(old_entryhi);
mtc0_tlbw_hazard();
local_irq_restore(flags);
return 0;
}
EXPORT_SYMBOL_GPL(kvm_mips_host_tlb_write);
int kvm_mips_handle_commpage_tlb_fault(unsigned long badvaddr,
struct kvm_vcpu *vcpu)
{
kvm: rename pfn_t to kvm_pfn_t To date, we have implemented two I/O usage models for persistent memory, PMEM (a persistent "ram disk") and DAX (mmap persistent memory into userspace). This series adds a third, DAX-GUP, that allows DAX mappings to be the target of direct-i/o. It allows userspace to coordinate DMA/RDMA from/to persistent memory. The implementation leverages the ZONE_DEVICE mm-zone that went into 4.3-rc1 (also discussed at kernel summit) to flag pages that are owned and dynamically mapped by a device driver. The pmem driver, after mapping a persistent memory range into the system memmap via devm_memremap_pages(), arranges for DAX to distinguish pfn-only versus page-backed pmem-pfns via flags in the new pfn_t type. The DAX code, upon seeing a PFN_DEV+PFN_MAP flagged pfn, flags the resulting pte(s) inserted into the process page tables with a new _PAGE_DEVMAP flag. Later, when get_user_pages() is walking ptes it keys off _PAGE_DEVMAP to pin the device hosting the page range active. Finally, get_page() and put_page() are modified to take references against the device driver established page mapping. Finally, this need for "struct page" for persistent memory requires memory capacity to store the memmap array. Given the memmap array for a large pool of persistent may exhaust available DRAM introduce a mechanism to allocate the memmap from persistent memory. The new "struct vmem_altmap *" parameter to devm_memremap_pages() enables arch_add_memory() to use reserved pmem capacity rather than the page allocator. This patch (of 18): The core has developed a need for a "pfn_t" type [1]. Move the existing pfn_t in KVM to kvm_pfn_t [2]. [1]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002199.html [2]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002218.html Signed-off-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-16 00:56:11 +00:00
kvm_pfn_t pfn0, pfn1;
unsigned long flags, old_entryhi = 0, vaddr = 0;
unsigned long entrylo0 = 0, entrylo1 = 0;
pfn0 = CPHYSADDR(vcpu->arch.kseg0_commpage) >> PAGE_SHIFT;
pfn1 = 0;
entrylo0 = mips3_paddr_to_tlbpfn(pfn0 << PAGE_SHIFT) | (0x3 << 3) |
(1 << 2) | (0x1 << 1);
entrylo1 = 0;
local_irq_save(flags);
old_entryhi = read_c0_entryhi();
vaddr = badvaddr & (PAGE_MASK << 1);
write_c0_entryhi(vaddr | kvm_mips_get_kernel_asid(vcpu));
write_c0_entrylo0(entrylo0);
write_c0_entrylo1(entrylo1);
write_c0_index(kvm_mips_get_commpage_asid(vcpu));
mtc0_tlbw_hazard();
tlb_write_indexed();
tlbw_use_hazard();
kvm_debug("@ %#lx idx: %2d [entryhi(R): %#lx] entrylo0 (R): 0x%08lx, entrylo1(R): 0x%08lx\n",
vcpu->arch.pc, read_c0_index(), read_c0_entryhi(),
read_c0_entrylo0(), read_c0_entrylo1());
/* Restore old ASID */
write_c0_entryhi(old_entryhi);
mtc0_tlbw_hazard();
local_irq_restore(flags);
return 0;
}
EXPORT_SYMBOL_GPL(kvm_mips_handle_commpage_tlb_fault);
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_lo0, tlb[i].tlb_lo1);
return index;
}
EXPORT_SYMBOL_GPL(kvm_mips_guest_tlb_lookup);
int kvm_mips_host_tlb_lookup(struct kvm_vcpu *vcpu, unsigned long vaddr)
{
unsigned long old_entryhi, flags;
int idx;
local_irq_save(flags);
old_entryhi = read_c0_entryhi();
if (KVM_GUEST_KERNEL_MODE(vcpu))
write_c0_entryhi((vaddr & VPN2_MASK) |
kvm_mips_get_kernel_asid(vcpu));
else {
write_c0_entryhi((vaddr & VPN2_MASK) |
kvm_mips_get_user_asid(vcpu));
}
mtc0_tlbw_hazard();
tlb_probe();
tlb_probe_hazard();
idx = read_c0_index();
/* Restore old ASID */
write_c0_entryhi(old_entryhi);
mtc0_tlbw_hazard();
local_irq_restore(flags);
kvm_debug("Host TLB lookup, %#lx, idx: %2d\n", vaddr, idx);
return idx;
}
EXPORT_SYMBOL_GPL(kvm_mips_host_tlb_lookup);
int kvm_mips_host_tlb_inv(struct kvm_vcpu *vcpu, unsigned long va)
{
int idx;
unsigned long flags, old_entryhi;
local_irq_save(flags);
old_entryhi = read_c0_entryhi();
write_c0_entryhi((va & VPN2_MASK) | kvm_mips_get_user_asid(vcpu));
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();
}
write_c0_entryhi(old_entryhi);
mtc0_tlbw_hazard();
local_irq_restore(flags);
if (idx > 0)
kvm_debug("%s: Invalidated entryhi %#lx @ idx %d\n", __func__,
(va & VPN2_MASK) | kvm_mips_get_user_asid(vcpu), idx);
return 0;
}
EXPORT_SYMBOL_GPL(kvm_mips_host_tlb_inv);
void kvm_mips_flush_host_tlb(int skip_kseg0)
{
unsigned long flags;
unsigned long old_entryhi, entryhi;
unsigned long old_pagemask;
int entry = 0;
int maxentry = current_cpu_data.tlbsize;
local_irq_save(flags);
old_entryhi = read_c0_entryhi();
old_pagemask = read_c0_pagemask();
/* Blast 'em all away. */
for (entry = 0; entry < maxentry; entry++) {
write_c0_index(entry);
if (skip_kseg0) {
mtc0_tlbr_hazard();
tlb_read();
tlb_read_hazard();
entryhi = read_c0_entryhi();
/* Don't blow away guest kernel entries */
if (KVM_GUEST_KSEGX(entryhi) == KVM_GUEST_KSEG0)
continue;
}
/* Make sure all entries differ. */
write_c0_entryhi(UNIQUE_ENTRYHI(entry));
write_c0_entrylo0(0);
write_c0_entrylo1(0);
mtc0_tlbw_hazard();
tlb_write_indexed();
tlbw_use_hazard();
}
write_c0_entryhi(old_entryhi);
write_c0_pagemask(old_pagemask);
mtc0_tlbw_hazard();
local_irq_restore(flags);
}
EXPORT_SYMBOL_GPL(kvm_mips_flush_host_tlb);
void kvm_local_flush_tlb_all(void)
{
unsigned long flags;
unsigned long old_ctx;
int entry = 0;
local_irq_save(flags);
/* Save old context and create impossible VPN2 value */
old_ctx = read_c0_entryhi();
write_c0_entrylo0(0);
write_c0_entrylo1(0);
/* Blast 'em all away. */
while (entry < current_cpu_data.tlbsize) {
/* Make sure all entries differ. */
write_c0_entryhi(UNIQUE_ENTRYHI(entry));
write_c0_index(entry);
mtc0_tlbw_hazard();
tlb_write_indexed();
tlbw_use_hazard();
entry++;
}
write_c0_entryhi(old_ctx);
mtc0_tlbw_hazard();
local_irq_restore(flags);
}
EXPORT_SYMBOL_GPL(kvm_local_flush_tlb_all);