cachepc-qemu

Fork of AMDESE/qemu with changes for cachepc side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-qemu
Log | Files | Refs | Submodules | LICENSE | sfeed.txt

qemu-coroutine-io.c (3201B)

      1/*
      2 * Coroutine-aware I/O functions
      3 *
      4 * Copyright (C) 2009-2010 Nippon Telegraph and Telephone Corporation.
      5 * Copyright (c) 2011, Red Hat, Inc.
      6 *
      7 * Permission is hereby granted, free of charge, to any person obtaining a copy
      8 * of this software and associated documentation files (the "Software"), to deal
      9 * in the Software without restriction, including without limitation the rights
     10 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
     11 * copies of the Software, and to permit persons to whom the Software is
     12 * furnished to do so, subject to the following conditions:
     13 *
     14 * The above copyright notice and this permission notice shall be included in
     15 * all copies or substantial portions of the Software.
     16 *
     17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
     18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
     19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
     20 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
     21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
     22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
     23 * THE SOFTWARE.
     24 */
     25#include "qemu/osdep.h"
     26#include "qemu-common.h"
     27#include "qemu/sockets.h"
     28#include "qemu/coroutine.h"
     29#include "qemu/iov.h"
     30#include "qemu/main-loop.h"
     31
     32ssize_t coroutine_fn
     33qemu_co_sendv_recvv(int sockfd, struct iovec *iov, unsigned iov_cnt,
     34                    size_t offset, size_t bytes, bool do_send)
     35{
     36    size_t done = 0;
     37    ssize_t ret;
     38    while (done < bytes) {
     39        ret = iov_send_recv(sockfd, iov, iov_cnt,
     40                            offset + done, bytes - done, do_send);
     41        if (ret > 0) {
     42            done += ret;
     43        } else if (ret < 0) {
     44            if (errno == EAGAIN || errno == EWOULDBLOCK) {
     45                qemu_coroutine_yield();
     46            } else if (done == 0) {
     47                return -errno;
     48            } else {
     49                break;
     50            }
     51        } else if (ret == 0 && !do_send) {
     52            /* write (send) should never return 0.
     53             * read (recv) returns 0 for end-of-file (-data).
     54             * In both cases there's little point retrying,
     55             * but we do for write anyway, just in case */
     56            break;
     57        }
     58    }
     59    return done;
     60}
     61
     62ssize_t coroutine_fn
     63qemu_co_send_recv(int sockfd, void *buf, size_t bytes, bool do_send)
     64{
     65    struct iovec iov = { .iov_base = buf, .iov_len = bytes };
     66    return qemu_co_sendv_recvv(sockfd, &iov, 1, 0, bytes, do_send);
     67}
     68
     69typedef struct {
     70    AioContext *ctx;
     71    Coroutine *co;
     72    int fd;
     73} FDYieldUntilData;
     74
     75static void fd_coroutine_enter(void *opaque)
     76{
     77    FDYieldUntilData *data = opaque;
     78    aio_set_fd_handler(data->ctx, data->fd, false, NULL, NULL, NULL, NULL);
     79    qemu_coroutine_enter(data->co);
     80}
     81
     82void coroutine_fn yield_until_fd_readable(int fd)
     83{
     84    FDYieldUntilData data;
     85
     86    assert(qemu_in_coroutine());
     87    data.ctx = qemu_get_current_aio_context();
     88    data.co = qemu_coroutine_self();
     89    data.fd = fd;
     90    aio_set_fd_handler(
     91        data.ctx, fd, false, fd_coroutine_enter, NULL, NULL, &data);
     92    qemu_coroutine_yield();
     93}