Commit 754cb9c0 authored by Yury Kotov's avatar Yury Kotov Committed by Dr. David Alan Gilbert
Browse files

exec: Change RAMBlockIterFunc definition 



Currently, qemu_ram_foreach_* calls RAMBlockIterFunc with many
block-specific arguments. But often iter func needs RAMBlock*.
This refactoring is needed for fast access to RAMBlock flags from
qemu_ram_foreach_block's callback. The only way to achieve this now
is to call qemu_ram_block_from_host (which also enumerates blocks).

So, this patch reduces complexity of
qemu_ram_foreach_block() -> cb() -> qemu_ram_block_from_host()
from O(n^2) to O(n).

Fix RAMBlockIterFunc definition and add some functions to read
RAMBlock* fields witch were passed.

Signed-off-by: default avatarYury Kotov <yury-kotov@yandex-team.ru>
Message-Id: <20190215174548.2630-2-yury-kotov@yandex-team.ru>
Reviewed-by: default avatarDr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: default avatarDr. David Alan Gilbert <dgilbert@redhat.com>
parent 9589e763

exec.c

+17 −4
Original line number Diff line number Diff line
@@ -1972,6 +1972,21 @@ const char *qemu_ram_get_idstr(RAMBlock *rb) 
    return rb->idstr;

}



void *qemu_ram_get_host_addr(RAMBlock *rb)

{

    return rb->host;

}



ram_addr_t qemu_ram_get_offset(RAMBlock *rb)

{

    return rb->offset;

}



ram_addr_t qemu_ram_get_used_length(RAMBlock *rb)

{

    return rb->used_length;

}



bool qemu_ram_is_shared(RAMBlock *rb)

{

    return rb->flags & RAM_SHARED;
@@ -3961,8 +3976,7 @@ int qemu_ram_foreach_block(RAMBlockIterFunc func, void *opaque) 


    rcu_read_lock();

    RAMBLOCK_FOREACH(block) {

        ret = func(block->idstr, block->host, block->offset,

                   block->used_length, opaque);

        ret = func(block, opaque);

        if (ret) {

            break;

        }
@@ -3981,8 +3995,7 @@ int qemu_ram_foreach_migratable_block(RAMBlockIterFunc func, void *opaque) 
        if (!qemu_ram_is_migratable(block)) {

            continue;

        }

        ret = func(block->idstr, block->host, block->offset,

                   block->used_length, opaque);

        ret = func(block, opaque);

        if (ret) {

            break;

        }

include/exec/cpu-common.h

+4 −2
Original line number Diff line number Diff line
@@ -72,6 +72,9 @@ ram_addr_t qemu_ram_block_host_offset(RAMBlock *rb, void *host); 
void qemu_ram_set_idstr(RAMBlock *block, const char *name, DeviceState *dev);

void qemu_ram_unset_idstr(RAMBlock *block);

const char *qemu_ram_get_idstr(RAMBlock *rb);

void *qemu_ram_get_host_addr(RAMBlock *rb);

ram_addr_t qemu_ram_get_offset(RAMBlock *rb);

ram_addr_t qemu_ram_get_used_length(RAMBlock *rb);

bool qemu_ram_is_shared(RAMBlock *rb);

bool qemu_ram_is_uf_zeroable(RAMBlock *rb);

void qemu_ram_set_uf_zeroable(RAMBlock *rb);
@@ -116,8 +119,7 @@ void cpu_flush_icache_range(hwaddr start, hwaddr len); 
extern struct MemoryRegion io_mem_rom;

extern struct MemoryRegion io_mem_notdirty;



typedef int (RAMBlockIterFunc)(const char *block_name, void *host_addr,

    ram_addr_t offset, ram_addr_t length, void *opaque);

typedef int (RAMBlockIterFunc)(RAMBlock *rb, void *opaque);



int qemu_ram_foreach_block(RAMBlockIterFunc func, void *opaque);

int qemu_ram_foreach_migratable_block(RAMBlockIterFunc func, void *opaque);

migration/postcopy-ram.c

+21 −15
Original line number Diff line number Diff line
@@ -319,10 +319,10 @@ static bool ufd_check_and_apply(int ufd, MigrationIncomingState *mis) 


/* Callback from postcopy_ram_supported_by_host block iterator.

 */

static int test_ramblock_postcopiable(const char *block_name, void *host_addr,

                             ram_addr_t offset, ram_addr_t length, void *opaque)

static int test_ramblock_postcopiable(RAMBlock *rb, void *opaque)

{

    RAMBlock *rb = qemu_ram_block_by_name(block_name);

    const char *block_name = qemu_ram_get_idstr(rb);

    ram_addr_t length = qemu_ram_get_used_length(rb);

    size_t pagesize = qemu_ram_pagesize(rb);



    if (length % pagesize) {
@@ -443,9 +443,12 @@ out: 
 * must be done right at the start prior to pre-copy.

 * opaque should be the MIS.

 */

static int init_range(const char *block_name, void *host_addr,

                      ram_addr_t offset, ram_addr_t length, void *opaque)

static int init_range(RAMBlock *rb, void *opaque)

{

    const char *block_name = qemu_ram_get_idstr(rb);

    void *host_addr = qemu_ram_get_host_addr(rb);

    ram_addr_t offset = qemu_ram_get_offset(rb);

    ram_addr_t length = qemu_ram_get_used_length(rb);

    trace_postcopy_init_range(block_name, host_addr, offset, length);



    /*
@@ -465,9 +468,12 @@ static int init_range(const char *block_name, void *host_addr, 
 * At the end of migration, undo the effects of init_range

 * opaque should be the MIS.

 */

static int cleanup_range(const char *block_name, void *host_addr,

                        ram_addr_t offset, ram_addr_t length, void *opaque)

static int cleanup_range(RAMBlock *rb, void *opaque)

{

    const char *block_name = qemu_ram_get_idstr(rb);

    void *host_addr = qemu_ram_get_host_addr(rb);

    ram_addr_t offset = qemu_ram_get_offset(rb);

    ram_addr_t length = qemu_ram_get_used_length(rb);

    MigrationIncomingState *mis = opaque;

    struct uffdio_range range_struct;

    trace_postcopy_cleanup_range(block_name, host_addr, offset, length);
@@ -586,9 +592,12 @@ int postcopy_ram_incoming_cleanup(MigrationIncomingState *mis) 
/*

 * Disable huge pages on an area

 */

static int nhp_range(const char *block_name, void *host_addr,

                    ram_addr_t offset, ram_addr_t length, void *opaque)

static int nhp_range(RAMBlock *rb, void *opaque)

{

    const char *block_name = qemu_ram_get_idstr(rb);

    void *host_addr = qemu_ram_get_host_addr(rb);

    ram_addr_t offset = qemu_ram_get_offset(rb);

    ram_addr_t length = qemu_ram_get_used_length(rb);

    trace_postcopy_nhp_range(block_name, host_addr, offset, length);



    /*
@@ -626,15 +635,13 @@ int postcopy_ram_prepare_discard(MigrationIncomingState *mis) 
 *   opaque: MigrationIncomingState pointer

 * Returns 0 on success

 */

static int ram_block_enable_notify(const char *block_name, void *host_addr,

                                   ram_addr_t offset, ram_addr_t length,

                                   void *opaque)

static int ram_block_enable_notify(RAMBlock *rb, void *opaque)

{

    MigrationIncomingState *mis = opaque;

    struct uffdio_register reg_struct;



    reg_struct.range.start = (uintptr_t)host_addr;

    reg_struct.range.len = length;

    reg_struct.range.start = (uintptr_t)qemu_ram_get_host_addr(rb);

    reg_struct.range.len = qemu_ram_get_used_length(rb);

    reg_struct.mode = UFFDIO_REGISTER_MODE_MISSING;



    /* Now tell our userfault_fd that it's responsible for this area */
@@ -647,7 +654,6 @@ static int ram_block_enable_notify(const char *block_name, void *host_addr, 
        return -1;

    }

    if (reg_struct.ioctls & ((__u64)1 << _UFFDIO_ZEROPAGE)) {

        RAMBlock *rb = qemu_ram_block_by_name(block_name);

        qemu_ram_set_uf_zeroable(rb);

    }

migration/rdma.c

+5 −2
Original line number Diff line number Diff line
@@ -624,9 +624,12 @@ static int rdma_add_block(RDMAContext *rdma, const char *block_name, 
 * in advanced before the migration starts. This tells us where the RAM blocks

 * are so that we can register them individually.

 */

static int qemu_rdma_init_one_block(const char *block_name, void *host_addr,

    ram_addr_t block_offset, ram_addr_t length, void *opaque)

static int qemu_rdma_init_one_block(RAMBlock *rb, void *opaque)

{

    const char *block_name = qemu_ram_get_idstr(rb);

    void *host_addr = qemu_ram_get_host_addr(rb);

    ram_addr_t block_offset = qemu_ram_get_offset(rb);

    ram_addr_t length = qemu_ram_get_used_length(rb);

    return rdma_add_block(opaque, block_name, host_addr, block_offset, length);

}

stubs/ram-block.c

+15 −0
Original line number Diff line number Diff line
@@ -2,6 +2,21 @@ 
#include "exec/ramlist.h"

#include "exec/cpu-common.h"



void *qemu_ram_get_host_addr(RAMBlock *rb)

{

    return 0;

}



ram_addr_t qemu_ram_get_offset(RAMBlock *rb)

{

    return 0;

}



ram_addr_t qemu_ram_get_used_length(RAMBlock *rb)

{

    return 0;

}



void ram_block_notifier_add(RAMBlockNotifier *n)

{

}