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page-xfer.c
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page-xfer.c
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#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include "crtools.h"
#include "page-xfer.h"
#include "page-pipe.h"
#include "protobuf.h"
#include "protobuf/pagemap.pb-c.h"
struct page_server_iov {
u32 cmd;
u32 nr_pages;
u64 vaddr;
u64 dst_id;
};
#define PS_IOV_ADD 1
#define PS_IOV_HOLE 2
#define PS_IOV_OPEN 3
#define PS_TYPE_BITS 8
#define PS_TYPE_MASK ((1 << PS_TYPE_BITS) - 1)
static inline u64 encode_pm_id(int type, long id)
{
return ((u64)id) << PS_TYPE_BITS | type;
}
static int decode_pm_type(u64 dst_id)
{
return dst_id & PS_TYPE_MASK;
}
static long decode_pm_id(u64 dst_id)
{
return (long)(dst_id >> PS_TYPE_BITS);
}
struct page_xfer_job {
u64 dst_id;
int p[2];
unsigned pipe_size;
struct page_xfer loc_xfer;
};
static struct page_xfer_job cxfer = {
.dst_id = ~0,
};
static void page_server_close(void)
{
if (cxfer.dst_id != ~0)
cxfer.loc_xfer.close(&cxfer.loc_xfer);
}
static int page_server_open(struct page_server_iov *pi)
{
int type;
long id;
type = decode_pm_type(pi->dst_id);
id = decode_pm_id(pi->dst_id);
pr_info("Opening %d/%ld\n", type, id);
page_server_close();
if (open_page_xfer(&cxfer.loc_xfer, type, id))
return -1;
cxfer.dst_id = pi->dst_id;
return 0;
}
static int prep_loc_xfer(struct page_server_iov *pi)
{
if (cxfer.dst_id != pi->dst_id) {
pr_warn("Deprecated IO w/o open\n");
return page_server_open(pi);
} else
return 0;
}
static int page_server_add(int sk, struct page_server_iov *pi)
{
size_t len;
struct page_xfer *lxfer = &cxfer.loc_xfer;
struct iovec iov;
pr_debug("Adding %"PRIx64"/%u\n", pi->vaddr, pi->nr_pages);
if (prep_loc_xfer(pi))
return -1;
iov.iov_base = decode_pointer(pi->vaddr);
iov.iov_len = pi->nr_pages * PAGE_SIZE;
if (lxfer->write_pagemap(lxfer, &iov))
return -1;
len = iov.iov_len;
while (len > 0) {
ssize_t chunk;
chunk = len;
if (chunk > cxfer.pipe_size)
chunk = cxfer.pipe_size;
chunk = splice(sk, NULL, cxfer.p[1], NULL, chunk, SPLICE_F_MOVE | SPLICE_F_NONBLOCK);
if (chunk < 0) {
pr_perror("Can't read from socket");
return -1;
}
if (lxfer->write_pages(lxfer, cxfer.p[0], chunk))
return -1;
len -= chunk;
}
return 0;
}
static int page_server_hole(int sk, struct page_server_iov *pi)
{
struct page_xfer *lxfer = &cxfer.loc_xfer;
struct iovec iov;
pr_debug("Adding %"PRIx64"/%u hole\n", pi->vaddr, pi->nr_pages);
if (prep_loc_xfer(pi))
return -1;
iov.iov_base = decode_pointer(pi->vaddr);
iov.iov_len = pi->nr_pages * PAGE_SIZE;
if (lxfer->write_hole(lxfer, &iov))
return -1;
return 0;
}
static int page_server_serve(int sk)
{
int ret = -1;
if (pipe(cxfer.p)) {
pr_perror("Can't make pipe for xfer");
close(sk);
return -1;
}
cxfer.pipe_size = fcntl(cxfer.p[0], F_GETPIPE_SZ, 0);
pr_debug("Created xfer pipe size %u\n", cxfer.pipe_size);
while (1) {
struct page_server_iov pi;
ret = read(sk, &pi, sizeof(pi));
if (!ret)
break;
if (ret != sizeof(pi)) {
pr_perror("Can't read pagemap from socket");
ret = -1;
break;
}
switch (pi.cmd) {
case PS_IOV_OPEN:
ret = page_server_open(&pi);
break;
case PS_IOV_ADD:
ret = page_server_add(sk, &pi);
break;
case PS_IOV_HOLE:
ret = page_server_hole(sk, &pi);
break;
default:
pr_err("Unknown command %u\n", pi.cmd);
ret = -1;
break;
}
if (ret)
break;
}
page_server_close();
pr_info("Session over\n");
close(sk);
return ret;
}
int cr_page_server(bool daemon_mode)
{
int sk, ask = -1;
struct sockaddr_in caddr;
socklen_t clen = sizeof(caddr);
up_page_ids_base();
pr_info("Starting page server on port %u\n",
(int)ntohs(opts.ps_addr.sin_port));
sk = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
if (sk < 0) {
pr_perror("Can't init page server");
return -1;
}
opts.ps_addr.sin_family = AF_INET;
if (bind(sk, (struct sockaddr *)&opts.ps_addr, sizeof(opts.ps_addr))) {
pr_perror("Can't bind page server");
goto out;
}
if (listen(sk, 1)) {
pr_perror("Can't listen on page server socket");
goto out;
}
if (daemon_mode)
daemon(0, 0);
ask = accept(sk, (struct sockaddr *)&caddr, &clen);
if (ask < 0)
pr_perror("Can't accept connection to server");
out:
close(sk);
if (ask < 0)
return -1;
pr_info("Accepted connection from %s:%u\n",
inet_ntoa(caddr.sin_addr),
(int)ntohs(caddr.sin_port));
return page_server_serve(ask);
}
static int page_server_sk = -1;
int connect_to_page_server(void)
{
if (!opts.use_page_server)
return 0;
pr_info("Connecting to server %s:%u\n",
inet_ntoa(opts.ps_addr.sin_addr),
(int)ntohs(opts.ps_addr.sin_port));
page_server_sk = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
if (page_server_sk < 0) {
pr_perror("Can't create socket");
return -1;
}
opts.ps_addr.sin_family = AF_INET;
if (connect(page_server_sk, (struct sockaddr *)&opts.ps_addr,
sizeof(opts.ps_addr)) < 0) {
pr_perror("Can't connect to server");
return -1;
}
return 0;
}
static int write_pagemap_to_server(struct page_xfer *xfer,
struct iovec *iov)
{
struct page_server_iov pi;
pi.cmd = PS_IOV_ADD;
pi.dst_id = xfer->dst_id;
pi.vaddr = encode_pointer(iov->iov_base);
pi.nr_pages = iov->iov_len / PAGE_SIZE;
if (write(xfer->fd, &pi, sizeof(pi)) != sizeof(pi)) {
pr_perror("Can't write pagemap to server");
return -1;
}
return 0;
}
static int write_pages_to_server(struct page_xfer *xfer,
int p, unsigned long len)
{
pr_debug("Splicing %lu bytes / %lu pages into socket\n", len, len / PAGE_SIZE);
if (splice(p, NULL, xfer->fd, NULL, len, SPLICE_F_MOVE) != len) {
pr_perror("Can't write pages to socket");
return -1;
}
return 0;
}
static int write_hole_to_server(struct page_xfer *xfer, struct iovec *iov)
{
struct page_server_iov pi;
pi.cmd = PS_IOV_HOLE;
pi.dst_id = xfer->dst_id;
pi.vaddr = encode_pointer(iov->iov_base);
pi.nr_pages = iov->iov_len / PAGE_SIZE;
if (write(xfer->fd, &pi, sizeof(pi)) != sizeof(pi)) {
pr_perror("Can't write pagehole to server");
return -1;
}
return 0;
}
static void close_server_xfer(struct page_xfer *xfer)
{
xfer->fd = -1;
}
static int open_page_server_xfer(struct page_xfer *xfer, int fd_type, long id)
{
struct page_server_iov pi;
xfer->fd = page_server_sk;
xfer->write_pagemap = write_pagemap_to_server;
xfer->write_pages = write_pages_to_server;
xfer->write_hole = write_hole_to_server;
xfer->close = close_server_xfer;
xfer->dst_id = encode_pm_id(fd_type, id);
pi.cmd = PS_IOV_OPEN;
pi.dst_id = xfer->dst_id;
pi.vaddr = 0;
pi.nr_pages = 0;
if (write(xfer->fd, &pi, sizeof(pi)) != sizeof(pi)) {
pr_perror("Can't write to page server");
return -1;
}
return 0;
}
static int write_pagemap_loc(struct page_xfer *xfer,
struct iovec *iov)
{
PagemapEntry pe = PAGEMAP_ENTRY__INIT;
pe.vaddr = encode_pointer(iov->iov_base);
pe.nr_pages = iov->iov_len / PAGE_SIZE;
return pb_write_one(xfer->fd, &pe, PB_PAGEMAP);
}
static int write_pages_loc(struct page_xfer *xfer,
int p, unsigned long len)
{
if (splice(p, NULL, xfer->fd_pg, NULL, len, SPLICE_F_MOVE) != len)
return -1;
return 0;
}
static int write_pagehole_loc(struct page_xfer *xfer, struct iovec *iov)
{
PagemapEntry pe = PAGEMAP_ENTRY__INIT;
pe.vaddr = encode_pointer(iov->iov_base);
pe.nr_pages = iov->iov_len / PAGE_SIZE;
pe.has_in_parent = true;
pe.in_parent = true;
if (pb_write_one(xfer->fd, &pe, PB_PAGEMAP) < 0)
return -1;
return 0;
}
static void close_page_xfer(struct page_xfer *xfer)
{
close(xfer->fd_pg);
close(xfer->fd);
}
int page_xfer_dump_pages(struct page_xfer *xfer, struct page_pipe *pp,
unsigned long off)
{
struct page_pipe_buf *ppb;
struct iovec *hole = NULL;
pr_debug("Transfering pages:\n");
if (pp->free_hole)
hole = &pp->holes[0];
list_for_each_entry(ppb, &pp->bufs, l) {
int i;
pr_debug("\tbuf %d/%d\n", ppb->pages_in, ppb->nr_segs);
for (i = 0; i < ppb->nr_segs; i++) {
struct iovec *iov = &ppb->iov[i];
while (hole && (hole->iov_base < iov->iov_base)) {
pr_debug("\th %p [%u]\n", hole->iov_base,
(unsigned int)(hole->iov_len / PAGE_SIZE));
if (xfer->write_hole(xfer, hole))
return -1;
hole++;
if (hole >= &pp->holes[pp->free_hole])
hole = NULL;
}
BUG_ON(iov->iov_base < (void *)off);
iov->iov_base -= off;
pr_debug("\tp %p [%u]\n", iov->iov_base,
(unsigned int)(iov->iov_len / PAGE_SIZE));
if (xfer->write_pagemap(xfer, iov))
return -1;
if (xfer->write_pages(xfer, ppb->p[0], iov->iov_len))
return -1;
}
}
while (hole) {
pr_debug("\th* %p [%u]\n", hole->iov_base,
(unsigned int)(hole->iov_len / PAGE_SIZE));
if (xfer->write_hole(xfer, hole))
return -1;
hole++;
if (hole >= &pp->holes[pp->free_hole])
hole = NULL;
}
return 0;
}
static int open_page_local_xfer(struct page_xfer *xfer, int fd_type, long id)
{
xfer->fd = open_image(fd_type, O_DUMP, id);
if (xfer->fd < 0)
return -1;
xfer->fd_pg = open_pages_image(O_DUMP, xfer->fd);
if (xfer->fd_pg < 0) {
close(xfer->fd);
return -1;
}
xfer->write_pagemap = write_pagemap_loc;
xfer->write_pages = write_pages_loc;
xfer->write_hole = write_pagehole_loc;
xfer->close = close_page_xfer;
return 0;
}
int open_page_xfer(struct page_xfer *xfer, int fd_type, long id)
{
if (opts.use_page_server)
return open_page_server_xfer(xfer, fd_type, id);
else
return open_page_local_xfer(xfer, fd_type, id);
}