On 2018-10-22 10:02, Yi Min Zhao wrote:
> Common function measurement block is used to report counters of
> successfully issued pcilg/stg/stb and rpcit instructions. This patch
> introduces a new struct ZpciFmb and schedules a timer callback to
> copy fmb to the guest memory at a interval time which is set to
> 4s by default. While attemping to update fmb failed, an event error
> would be generated. After pcilg/stg/stb and rpcit interception
> handlers issue successfully, increase the related counter. The guest
> could pass null address to switch off FMB and stop corresponding
> timer.
>
> Signed-off-by: Yi Min Zhao <zyi...@linux.ibm.com>
> Reviewed-by: Pierre Morel <pmo...@linux.ibm.com>
> ---
[...]
> +static int fmb_do_update(S390PCIBusDevice *pbdev, uint8_t offset, int len)
> +{
> + MemTxResult ret;
> +
> + ret = address_space_write(&address_space_memory,
> + pbdev->fmb_addr + (uint64_t)offset,
> + MEMTXATTRS_UNSPECIFIED,
> + (uint8_t *)&pbdev->fmb + offset,
> + len);
> + if (ret) {
> + s390_pci_generate_error_event(ERR_EVENT_FMBA, pbdev->fh, pbdev->fid,
> + pbdev->fmb_addr, 0);
> + fmb_timer_free(pbdev);
> + }
> +
> + return ret;
> +}
> +
> +static void fmb_update(void *opaque)
> +{
> + S390PCIBusDevice *pbdev = opaque;
> + int64_t t = qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL);
> + uint8_t offset = offsetof(ZpciFmb, last_update);
> +
> + /* Update U bit */
> + pbdev->fmb.last_update |= UPDATE_U_BIT;
> + if (fmb_do_update(pbdev, offset, sizeof(uint64_t))) {
> + return;
> + }
> +
> + /* Update FMB counters */
> + pbdev->fmb.sample++;
> + if (fmb_do_update(pbdev, 0, sizeof(ZpciFmb))) {
> + return;
> + }
> +
> + /* Clear U bit and update the time */
> + pbdev->fmb.last_update = time2tod(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL));
> + pbdev->fmb.last_update &= ~UPDATE_U_BIT;
> + if (fmb_do_update(pbdev, offset, sizeof(uint64_t))) {
> + return;
> + }
> +
> + timer_mod(pbdev->fmb_timer, t + DEFAULT_MUI);
> +}
Sorry for noticing this in v1 already, but is this code endianess-safe?
I.e. can this also work with qemu-system-s390x running with TCG on a x86
host? I think you might have to use something like this here instead:
pbdev->fmb.sample = cpu_to_be32(be32_to_cpu(pbdev->fmb.sample) + 1);
etc.
Thomas
