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cputlb: add tlb_flush_by_mmuidx async routines

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This converts the remaining TLB flush routines to use async work when
detecting a cross-vCPU flush. The only minor complication is having to
serialise the var_list of MMU indexes into a form that can be punted
to an asynchronous job.

The pending_tlb_flush field on QOM's CPU structure also becomes a
bitfield rather than a boolean.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
This commit is contained in:
Alex Bennée 2017-02-23 18:29:20 +00:00
parent 0336cbf853
commit e72184455c
2 changed files with 89 additions and 23 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

110
cputlb.c
View File

@ -68,6 +68,11 @@
* target_ulong even on 32 bit builds */
QEMU_BUILD_BUG_ON(sizeof(target_ulong) > sizeof(run_on_cpu_data));
/* We currently can't handle more than 16 bits in the MMUIDX bitmask.
*/
QEMU_BUILD_BUG_ON(NB_MMU_MODES > 16);
#define ALL_MMUIDX_BITS ((1 << NB_MMU_MODES) - 1)
/* statistics */
int tlb_flush_count;
@ -102,7 +107,7 @@ static void tlb_flush_nocheck(CPUState *cpu)
tb_unlock();
atomic_mb_set(&cpu->pending_tlb_flush, false);
atomic_mb_set(&cpu->pending_tlb_flush, 0);
}
static void tlb_flush_global_async_work(CPUState *cpu, run_on_cpu_data data)
@ -113,7 +118,8 @@ static void tlb_flush_global_async_work(CPUState *cpu, run_on_cpu_data data)
void tlb_flush(CPUState *cpu)
{
if (cpu->created && !qemu_cpu_is_self(cpu)) {
if (atomic_cmpxchg(&cpu->pending_tlb_flush, false, true) == true) {
if (atomic_mb_read(&cpu->pending_tlb_flush) != ALL_MMUIDX_BITS) {
atomic_mb_set(&cpu->pending_tlb_flush, ALL_MMUIDX_BITS);
async_run_on_cpu(cpu, tlb_flush_global_async_work,
RUN_ON_CPU_NULL);
}
@ -122,17 +128,18 @@ void tlb_flush(CPUState *cpu)
}
}
static inline void v_tlb_flush_by_mmuidx(CPUState *cpu, uint16_t idxmap)
static void tlb_flush_by_mmuidx_async_work(CPUState *cpu, run_on_cpu_data data)
{
CPUArchState *env = cpu->env_ptr;
unsigned long mmu_idx_bitmask = idxmap;
unsigned long mmu_idx_bitmask = data.host_int;
int mmu_idx;
assert_cpu_is_self(cpu);
tlb_debug("start\n");
tb_lock();
tlb_debug("start: mmu_idx:0x%04lx\n", mmu_idx_bitmask);
for (mmu_idx = 0; mmu_idx < NB_MMU_MODES; mmu_idx++) {
if (test_bit(mmu_idx, &mmu_idx_bitmask)) {
@ -145,12 +152,30 @@ static inline void v_tlb_flush_by_mmuidx(CPUState *cpu, uint16_t idxmap)
memset(cpu->tb_jmp_cache, 0, sizeof(cpu->tb_jmp_cache));
tlb_debug("done\n");
tb_unlock();
}
void tlb_flush_by_mmuidx(CPUState *cpu, uint16_t idxmap)
{
v_tlb_flush_by_mmuidx(cpu, idxmap);
tlb_debug("mmu_idx: 0x%" PRIx16 "\n", idxmap);
if (!qemu_cpu_is_self(cpu)) {
uint16_t pending_flushes = idxmap;
pending_flushes &= ~atomic_mb_read(&cpu->pending_tlb_flush);
if (pending_flushes) {
tlb_debug("reduced mmu_idx: 0x%" PRIx16 "\n", pending_flushes);
atomic_or(&cpu->pending_tlb_flush, pending_flushes);
async_run_on_cpu(cpu, tlb_flush_by_mmuidx_async_work,
RUN_ON_CPU_HOST_INT(pending_flushes));
}
} else {
tlb_flush_by_mmuidx_async_work(cpu,
RUN_ON_CPU_HOST_INT(idxmap));
}
}
static inline void tlb_flush_entry(CPUTLBEntry *tlb_entry, target_ulong addr)
@ -215,27 +240,26 @@ void tlb_flush_page(CPUState *cpu, target_ulong addr)
}
}
void tlb_flush_page_by_mmuidx(CPUState *cpu, target_ulong addr, uint16_t idxmap)
/* As we are going to hijack the bottom bits of the page address for a
* mmuidx bit mask we need to fail to build if we can't do that
*/
QEMU_BUILD_BUG_ON(NB_MMU_MODES > TARGET_PAGE_BITS_MIN);
static void tlb_flush_page_by_mmuidx_async_work(CPUState *cpu,
run_on_cpu_data data)
{
CPUArchState *env = cpu->env_ptr;
unsigned long mmu_idx_bitmap = idxmap;
int i, page, mmu_idx;
target_ulong addr_and_mmuidx = (target_ulong) data.target_ptr;
target_ulong addr = addr_and_mmuidx & TARGET_PAGE_MASK;
unsigned long mmu_idx_bitmap = addr_and_mmuidx & ALL_MMUIDX_BITS;
int page = (addr >> TARGET_PAGE_BITS) & (CPU_TLB_SIZE - 1);
int mmu_idx;
int i;
assert_cpu_is_self(cpu);
tlb_debug("addr "TARGET_FMT_lx"\n", addr);
/* Check if we need to flush due to large pages. */
if ((addr & env->tlb_flush_mask) == env->tlb_flush_addr) {
tlb_debug("forced full flush ("
TARGET_FMT_lx "/" TARGET_FMT_lx ")\n",
env->tlb_flush_addr, env->tlb_flush_mask);
v_tlb_flush_by_mmuidx(cpu, idxmap);
return;
}
addr &= TARGET_PAGE_MASK;
page = (addr >> TARGET_PAGE_BITS) & (CPU_TLB_SIZE - 1);
tlb_debug("page:%d addr:"TARGET_FMT_lx" mmu_idx:0x%lx\n",
page, addr, mmu_idx_bitmap);
for (mmu_idx = 0; mmu_idx < NB_MMU_MODES; mmu_idx++) {
if (test_bit(mmu_idx, &mmu_idx_bitmap)) {
@ -251,6 +275,48 @@ void tlb_flush_page_by_mmuidx(CPUState *cpu, target_ulong addr, uint16_t idxmap)
tb_flush_jmp_cache(cpu, addr);
}
static void tlb_check_page_and_flush_by_mmuidx_async_work(CPUState *cpu,
run_on_cpu_data data)
{
CPUArchState *env = cpu->env_ptr;
target_ulong addr_and_mmuidx = (target_ulong) data.target_ptr;
target_ulong addr = addr_and_mmuidx & TARGET_PAGE_MASK;
unsigned long mmu_idx_bitmap = addr_and_mmuidx & ALL_MMUIDX_BITS;
tlb_debug("addr:"TARGET_FMT_lx" mmu_idx: %04lx\n", addr, mmu_idx_bitmap);
/* Check if we need to flush due to large pages. */
if ((addr & env->tlb_flush_mask) == env->tlb_flush_addr) {
tlb_debug("forced full flush ("
TARGET_FMT_lx "/" TARGET_FMT_lx ")\n",
env->tlb_flush_addr, env->tlb_flush_mask);
tlb_flush_by_mmuidx_async_work(cpu,
RUN_ON_CPU_HOST_INT(mmu_idx_bitmap));
} else {
tlb_flush_page_by_mmuidx_async_work(cpu, data);
}
}
void tlb_flush_page_by_mmuidx(CPUState *cpu, target_ulong addr, uint16_t idxmap)
{
target_ulong addr_and_mmu_idx;
tlb_debug("addr: "TARGET_FMT_lx" mmu_idx:%" PRIx16 "\n", addr, idxmap);
/* This should already be page aligned */
addr_and_mmu_idx = addr & TARGET_PAGE_MASK;
addr_and_mmu_idx |= idxmap;
if (!qemu_cpu_is_self(cpu)) {
async_run_on_cpu(cpu, tlb_check_page_and_flush_by_mmuidx_async_work,
RUN_ON_CPU_TARGET_PTR(addr_and_mmu_idx));
} else {
tlb_check_page_and_flush_by_mmuidx_async_work(
cpu, RUN_ON_CPU_TARGET_PTR(addr_and_mmu_idx));
}
}
void tlb_flush_page_all(target_ulong addr)
{
CPUState *cpu;

2
include/qom/cpu.h
View File

@ -407,7 +407,7 @@ struct CPUState {
* avoid potential races. The aim of the flag is to avoid
* unnecessary flushes.
*/
bool pending_tlb_flush;
uint16_t pending_tlb_flush;
};
QTAILQ_HEAD(CPUTailQ, CPUState);