[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH v5 33/45] Page request: Process incoming page re
From: |
David Gibson |
Subject: |
Re: [Qemu-devel] [PATCH v5 33/45] Page request: Process incoming page request |
Date: |
Tue, 24 Mar 2015 12:53:07 +1100 |
User-agent: |
Mutt/1.5.23 (2014-03-12) |
On Wed, Feb 25, 2015 at 04:51:56PM +0000, Dr. David Alan Gilbert (git) wrote:
> From: "Dr. David Alan Gilbert" <address@hidden>
>
> On receiving MIG_RPCOMM_REQ_PAGES look up the address and
> queue the page.
>
> Signed-off-by: Dr. David Alan Gilbert <address@hidden>
> ---
> arch_init.c | 55
> +++++++++++++++++++++++++++++++++++++++++++
> include/exec/cpu-all.h | 2 --
> include/migration/migration.h | 21 +++++++++++++++++
> include/qemu/typedefs.h | 1 +
> migration/migration.c | 33 +++++++++++++++++++++++++-
> trace-events | 3 ++-
> 6 files changed, 111 insertions(+), 4 deletions(-)
>
> diff --git a/arch_init.c b/arch_init.c
> index d2c4457..9d8fc6b 100644
> --- a/arch_init.c
> +++ b/arch_init.c
> @@ -669,6 +669,61 @@ static int ram_save_page(QEMUFile *f, RAMBlock* block,
> ram_addr_t offset,
> }
>
> /*
> + * Queue the pages for transmission, e.g. a request from postcopy destination
> + * ms: MigrationStatus in which the queue is held
> + * rbname: The RAMBlock the request is for - may be NULL (to mean reuse
> last)
> + * start: Offset from the start of the RAMBlock
> + * len: Length (in bytes) to send
> + * Return: 0 on success
> + */
> +int ram_save_queue_pages(MigrationState *ms, const char *rbname,
> + ram_addr_t start, ram_addr_t len)
> +{
> + RAMBlock *ramblock;
> +
> + if (!rbname) {
> + /* Reuse last RAMBlock */
> + ramblock = ms->last_req_rb;
> +
> + if (!ramblock) {
> + /*
> + * Shouldn't happen, we can't reuse the last RAMBlock if
> + * it's the 1st request.
> + */
> + error_report("ram_save_queue_pages no previous block");
> + return -1;
> + }
> + } else {
> + ramblock = ram_find_block(rbname);
> +
> + if (!ramblock) {
> + /* We shouldn't be asked for a non-existent RAMBlock */
> + error_report("ram_save_queue_pages no block '%s'", rbname);
> + return -1;
> + }
> + }
> + trace_ram_save_queue_pages(ramblock->idstr, start, len);
> + if (start+len > ramblock->used_length) {
> + error_report("%s request overrun start=%zx len=%zx blocklen=%zx",
> + __func__, start, len, ramblock->used_length);
> + return -1;
> + }
> +
> + struct MigrationSrcPageRequest *new_entry =
> + g_malloc0(sizeof(struct MigrationSrcPageRequest));
> + new_entry->rb = ramblock;
> + new_entry->offset = start;
> + new_entry->len = len;
> + ms->last_req_rb = ramblock;
> +
> + qemu_mutex_lock(&ms->src_page_req_mutex);
> + QSIMPLEQ_INSERT_TAIL(&ms->src_page_requests, new_entry, next_req);
> + qemu_mutex_unlock(&ms->src_page_req_mutex);
> +
> + return 0;
> +}
> +
> +/*
> * ram_find_and_save_block: Finds a page to send and sends it to f
> *
> * Returns: The number of bytes written.
> diff --git a/include/exec/cpu-all.h b/include/exec/cpu-all.h
> index 2c48286..3088000 100644
> --- a/include/exec/cpu-all.h
> +++ b/include/exec/cpu-all.h
> @@ -265,8 +265,6 @@ CPUArchState *cpu_copy(CPUArchState *env);
>
> /* memory API */
>
> -typedef struct RAMBlock RAMBlock;
> -
> struct RAMBlock {
> struct MemoryRegion *mr;
> uint8_t *host;
> diff --git a/include/migration/migration.h b/include/migration/migration.h
> index 2c15d63..b1c7cad 100644
> --- a/include/migration/migration.h
> +++ b/include/migration/migration.h
> @@ -100,6 +100,18 @@ MigrationIncomingState
> *migration_incoming_get_current(void);
> MigrationIncomingState *migration_incoming_state_new(QEMUFile *f);
> void migration_incoming_state_destroy(void);
>
> +/*
> + * An outstanding page request, on the source, having been received
> + * and queued
> + */
> +struct MigrationSrcPageRequest {
> + RAMBlock *rb;
> + hwaddr offset;
> + hwaddr len;
> +
> + QSIMPLEQ_ENTRY(MigrationSrcPageRequest) next_req;
> +};
> +
> struct MigrationState
> {
> int64_t bandwidth_limit;
> @@ -142,6 +154,12 @@ struct MigrationState
> * of the postcopy phase
> */
> unsigned long *sentmap;
> +
> + /* Queue of outstanding page requests from the destination */
> + QemuMutex src_page_req_mutex;
> + QSIMPLEQ_HEAD(src_page_requests, MigrationSrcPageRequest)
> src_page_requests;
> + /* The RAMBlock used in the last src_page_request */
> + RAMBlock *last_req_rb;
> };
>
> void process_incoming_migration(QEMUFile *f);
> @@ -276,6 +294,9 @@ size_t ram_control_save_page(QEMUFile *f, ram_addr_t
> block_offset,
> ram_addr_t offset, size_t size,
> int *bytes_sent);
>
> +int ram_save_queue_pages(MigrationState *ms, const char *rbname,
> + ram_addr_t start, ram_addr_t len);
> +
> PostcopyState postcopy_state_get(MigrationIncomingState *mis);
>
> /* Set the state and return the old state */
> diff --git a/include/qemu/typedefs.h b/include/qemu/typedefs.h
> index 0651275..396044d 100644
> --- a/include/qemu/typedefs.h
> +++ b/include/qemu/typedefs.h
> @@ -73,6 +73,7 @@ typedef struct QEMUSGList QEMUSGList;
> typedef struct QEMUSizedBuffer QEMUSizedBuffer;
> typedef struct QEMUTimerListGroup QEMUTimerListGroup;
> typedef struct QEMUTimer QEMUTimer;
> +typedef struct RAMBlock RAMBlock;
> typedef struct Range Range;
> typedef struct SerialState SerialState;
> typedef struct SHPCDevice SHPCDevice;
> diff --git a/migration/migration.c b/migration/migration.c
> index 2e9d0dd..939f426 100644
> --- a/migration/migration.c
> +++ b/migration/migration.c
> @@ -26,6 +26,8 @@
> #include "qemu/thread.h"
> #include "qmp-commands.h"
> #include "trace.h"
> +#include "exec/memory.h"
> +#include "exec/address-spaces.h"
>
> enum MigrationPhase {
> MIG_STATE_ERROR = -1,
> @@ -495,6 +497,15 @@ static void migrate_fd_cleanup(void *opaque)
>
> migrate_fd_cleanup_src_rp(s);
>
> + /* This queue generally should be empty - but in the case of a failed
> + * migration might have some droppings in.
> + */
> + struct MigrationSrcPageRequest *mspr, *next_mspr;
> + QSIMPLEQ_FOREACH_SAFE(mspr, &s->src_page_requests, next_req, next_mspr) {
> + QSIMPLEQ_REMOVE_HEAD(&s->src_page_requests, next_req);
> + g_free(mspr);
> + }
> +
> if (s->file) {
> trace_migrate_fd_cleanup();
> qemu_mutex_unlock_iothread();
> @@ -613,6 +624,9 @@ MigrationState *migrate_init(const MigrationParams
> *params)
> s->state = MIG_STATE_SETUP;
> trace_migrate_set_state(MIG_STATE_SETUP);
>
> + qemu_mutex_init(&s->src_page_req_mutex);
> + QSIMPLEQ_INIT(&s->src_page_requests);
> +
> s->total_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
> return s;
> }
> @@ -826,7 +840,24 @@ static void source_return_path_bad(MigrationState *s)
> static void migrate_handle_rp_req_pages(MigrationState *ms, const char*
> rbname,
> ram_addr_t start, ram_addr_t len)
> {
> - trace_migrate_handle_rp_req_pages(start, len);
> + trace_migrate_handle_rp_req_pages(rbname, start, len);
> +
> + /* Round everything up to our host page size */
> + long our_host_ps = getpagesize();
> + if (start & (our_host_ps-1)) {
> + long roundings = start & (our_host_ps-1);
> + start -= roundings;
> + len += roundings;
> + }
> + if (len & (our_host_ps-1)) {
> + long roundings = len & (our_host_ps-1);
> + len -= roundings;
> + len += our_host_ps;
> + }
Why is it necessary to round out to host page size on the source? I
understand why the host page size is relevant on the destination, due
to the userfaultfd and atomic populate constraints, but not on the source.
> + if (ram_save_queue_pages(ms, rbname, start, len)) {
> + source_return_path_bad(ms);
> + }
> }
>
> /*
> diff --git a/trace-events b/trace-events
> index 9bedee4..8a0d70d 100644
> --- a/trace-events
> +++ b/trace-events
> @@ -1218,6 +1218,7 @@ migration_bitmap_sync_start(void) ""
> migration_bitmap_sync_end(uint64_t dirty_pages) "dirty_pages %" PRIu64""
> migration_throttle(void) ""
> ram_postcopy_send_discard_bitmap(void) ""
> +ram_save_queue_pages(const char *rbname, size_t start, size_t len) "%s:
> start: %zx len: %zx"
>
> # hw/display/qxl.c
> disable qxl_interface_set_mm_time(int qid, uint32_t mm_time) "%d %d"
> @@ -1404,7 +1405,7 @@ migrate_fd_error(void) ""
> migrate_fd_cancel(void) ""
> migrate_pending(uint64_t size, uint64_t max, uint64_t post, uint64_t
> nonpost) "pending size %" PRIu64 " max %" PRIu64 " (post=%" PRIu64 "
> nonpost=%" PRIu64 ")"
> migrate_send_rp_message(int cmd, uint16_t len) "cmd=%d, len=%d"
> -migrate_handle_rp_req_pages(size_t start, size_t len) "at %zx for len %zx"
> +migrate_handle_rp_req_pages(const char *rbname, size_t start, size_t len)
> "in %s at %zx len %zx"
> migration_thread_after_loop(void) ""
> migration_thread_file_err(void) ""
> migration_thread_setup_complete(void) ""
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
pgpULhqi0G2BN.pgp
Description: PGP signature
- Re: [Qemu-devel] [PATCH v5 33/45] Page request: Process incoming page request,
David Gibson <=