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

pvrdma_dev_ring.c (3800B)

      1/*
      2 * QEMU paravirtual RDMA - Device rings
      3 *
      4 * Copyright (C) 2018 Oracle
      5 * Copyright (C) 2018 Red Hat Inc
      6 *
      7 * Authors:
      8 *     Yuval Shaia <yuval.shaia@oracle.com>
      9 *     Marcel Apfelbaum <marcel@redhat.com>
     10 *
     11 * This work is licensed under the terms of the GNU GPL, version 2 or later.
     12 * See the COPYING file in the top-level directory.
     13 *
     14 */
     15
     16#include "qemu/osdep.h"
     17#include "qemu/cutils.h"
     18#include "hw/pci/pci.h"
     19#include "cpu.h"
     20#include "qemu/cutils.h"
     21
     22#include "trace.h"
     23
     24#include "../rdma_utils.h"
     25#include "pvrdma_dev_ring.h"
     26
     27int pvrdma_ring_init(PvrdmaRing *ring, const char *name, PCIDevice *dev,
     28                     PvrdmaRingState *ring_state, uint32_t max_elems,
     29                     size_t elem_sz, dma_addr_t *tbl, uint32_t npages)
     30{
     31    int i;
     32    int rc = 0;
     33
     34    pstrcpy(ring->name, MAX_RING_NAME_SZ, name);
     35    ring->dev = dev;
     36    ring->ring_state = ring_state;
     37    ring->max_elems = max_elems;
     38    ring->elem_sz = elem_sz;
     39    /* TODO: Give a moment to think if we want to redo driver settings
     40    qatomic_set(&ring->ring_state->prod_tail, 0);
     41    qatomic_set(&ring->ring_state->cons_head, 0);
     42    */
     43    ring->npages = npages;
     44    ring->pages = g_malloc0(npages * sizeof(void *));
     45
     46    for (i = 0; i < npages; i++) {
     47        if (!tbl[i]) {
     48            rdma_error_report("npages=%d but tbl[%d] is NULL", npages, i);
     49            continue;
     50        }
     51
     52        ring->pages[i] = rdma_pci_dma_map(dev, tbl[i], TARGET_PAGE_SIZE);
     53        if (!ring->pages[i]) {
     54            rc = -ENOMEM;
     55            rdma_error_report("Failed to map to page %d in ring %s", i, name);
     56            goto out_free;
     57        }
     58        memset(ring->pages[i], 0, TARGET_PAGE_SIZE);
     59    }
     60
     61    goto out;
     62
     63out_free:
     64    while (i--) {
     65        rdma_pci_dma_unmap(dev, ring->pages[i], TARGET_PAGE_SIZE);
     66    }
     67    g_free(ring->pages);
     68
     69out:
     70    return rc;
     71}
     72
     73void *pvrdma_ring_next_elem_read(PvrdmaRing *ring)
     74{
     75    unsigned int idx, offset;
     76    const uint32_t tail = qatomic_read(&ring->ring_state->prod_tail);
     77    const uint32_t head = qatomic_read(&ring->ring_state->cons_head);
     78
     79    if (tail & ~((ring->max_elems << 1) - 1) ||
     80        head & ~((ring->max_elems << 1) - 1) ||
     81        tail == head) {
     82        trace_pvrdma_ring_next_elem_read_no_data(ring->name);
     83        return NULL;
     84    }
     85
     86    idx = head & (ring->max_elems - 1);
     87    offset = idx * ring->elem_sz;
     88    return ring->pages[offset / TARGET_PAGE_SIZE] + (offset % TARGET_PAGE_SIZE);
     89}
     90
     91void pvrdma_ring_read_inc(PvrdmaRing *ring)
     92{
     93    uint32_t idx = qatomic_read(&ring->ring_state->cons_head);
     94
     95    idx = (idx + 1) & ((ring->max_elems << 1) - 1);
     96    qatomic_set(&ring->ring_state->cons_head, idx);
     97}
     98
     99void *pvrdma_ring_next_elem_write(PvrdmaRing *ring)
    100{
    101    unsigned int idx, offset;
    102    const uint32_t tail = qatomic_read(&ring->ring_state->prod_tail);
    103    const uint32_t head = qatomic_read(&ring->ring_state->cons_head);
    104
    105    if (tail & ~((ring->max_elems << 1) - 1) ||
    106        head & ~((ring->max_elems << 1) - 1) ||
    107        tail == (head ^ ring->max_elems)) {
    108        rdma_error_report("CQ is full");
    109        return NULL;
    110    }
    111
    112    idx = tail & (ring->max_elems - 1);
    113    offset = idx * ring->elem_sz;
    114    return ring->pages[offset / TARGET_PAGE_SIZE] + (offset % TARGET_PAGE_SIZE);
    115}
    116
    117void pvrdma_ring_write_inc(PvrdmaRing *ring)
    118{
    119    uint32_t idx = qatomic_read(&ring->ring_state->prod_tail);
    120
    121    idx = (idx + 1) & ((ring->max_elems << 1) - 1);
    122    qatomic_set(&ring->ring_state->prod_tail, idx);
    123}
    124
    125void pvrdma_ring_free(PvrdmaRing *ring)
    126{
    127    if (!ring) {
    128        return;
    129    }
    130
    131    if (!ring->pages) {
    132        return;
    133    }
    134
    135    while (ring->npages--) {
    136        rdma_pci_dma_unmap(ring->dev, ring->pages[ring->npages],
    137                           TARGET_PAGE_SIZE);
    138    }
    139
    140    g_free(ring->pages);
    141    ring->pages = NULL;
    142}