From: Hongyong Zang <zanghongyong@xxxxxxxxxx>
When a guest boots with ioeventfd, an error (by gdb) occurs:
Program received signal SIGSEGV, Segmentation fault.
0x00000000006009cc in setup_ioeventfds (s=0x171dc40)
at /home/louzhengwei/git_source/qemu-kvm/hw/ivshmem.c:363
363 for (j = 0; j < s->peers[i].nb_eventfds; j++) {
The bug is due to accessing s->peers which is NULL.
This patch uses the memory region API to replace the old one kvm_set_ioeventfd_mmio_long().
And this patch makes memory_region_add_eventfd() called in ivshmem_read() when qemu receives
eventfd information from ivshmem_server.
Signed-off-by: Hongyong Zang <zanghongyong@xxxxxxxxxx>
---
hw/ivshmem.c | 41 ++++++++++++++---------------------------
1 files changed, 14 insertions(+), 27 deletions(-)
diff --git a/hw/ivshmem.c b/hw/ivshmem.c
index 242fbea..be26f03 100644
--- a/hw/ivshmem.c
+++ b/hw/ivshmem.c
@@ -58,7 +58,6 @@ typedef struct IVShmemState {
CharDriverState *server_chr;
MemoryRegion ivshmem_mmio;
- pcibus_t mmio_addr;
/* We might need to register the BAR before we actually have the memory.
* So prepare a container MemoryRegion for the BAR immediately and
* add a subregion when we have the memory.
@@ -346,8 +345,14 @@ static void close_guest_eventfds(IVShmemState *s, int posn)
guest_curr_max = s->peers[posn].nb_eventfds;
for (i = 0; i < guest_curr_max; i++) {
- kvm_set_ioeventfd_mmio_long(s->peers[posn].eventfds[i],
- s->mmio_addr + DOORBELL, (posn << 16) | i, 0);
+ if (ivshmem_has_feature(s, IVSHMEM_IOEVENTFD)) {
+ memory_region_del_eventfd(&s->ivshmem_mmio,
+ DOORBELL,
+ 4,
+ true,
+ (posn << 16) | i,
+ s->peers[posn].eventfds[i]);
+ }
close(s->peers[posn].eventfds[i]);
}
@@ -355,22 +360,6 @@ static void close_guest_eventfds(IVShmemState *s, int posn)
s->peers[posn].nb_eventfds = 0;
}
-static void setup_ioeventfds(IVShmemState *s) {
-
- int i, j;
-
- for (i = 0; i <= s->max_peer; i++) {
- for (j = 0; j < s->peers[i].nb_eventfds; j++) {
- memory_region_add_eventfd(&s->ivshmem_mmio,
- DOORBELL,
- 4,
- true,
- (i << 16) | j,
- s->peers[i].eventfds[j]);
- }
- }
-}
-
/* this function increase the dynamic storage need to store data about other
* guests */
static void increase_dynamic_storage(IVShmemState *s, int new_min_size) {
@@ -491,10 +480,12 @@ static void ivshmem_read(void *opaque, const uint8_t * buf, int flags)
}
if (ivshmem_has_feature(s, IVSHMEM_IOEVENTFD)) {
- if (kvm_set_ioeventfd_mmio_long(incoming_fd, s->mmio_addr + DOORBELL,
- (incoming_posn << 16) | guest_max_eventfd, 1) < 0) {
- fprintf(stderr, "ivshmem: ioeventfd not available\n");
- }
+ memory_region_add_eventfd(&s->ivshmem_mmio,
+ DOORBELL,
+ 4,
+ true,
+ (incoming_posn << 16) | guest_max_eventfd,
+ incoming_fd);
}
return;
@@ -659,10 +650,6 @@ static int pci_ivshmem_init(PCIDevice *dev)
memory_region_init_io(&s->ivshmem_mmio, &ivshmem_mmio_ops, s,
"ivshmem-mmio", IVSHMEM_REG_BAR_SIZE);
- if (ivshmem_has_feature(s, IVSHMEM_IOEVENTFD)) {
- setup_ioeventfds(s);
- }
-
/* region for registers*/
pci_register_bar(&s->dev, 0, PCI_BASE_ADDRESS_SPACE_MEMORY,
&s->ivshmem_mmio);
--
1.7.1
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