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Re: [Qemu-devel] [PATCH v2 3/8] s390x: improve error handling for SSCH a
From: |
Dong Jia Shi |
Subject: |
Re: [Qemu-devel] [PATCH v2 3/8] s390x: improve error handling for SSCH and RSCH |
Date: |
Wed, 11 Oct 2017 11:47:56 +0800 |
User-agent: |
Mutt/1.5.21 (2010-09-15) |
* Halil Pasic <address@hidden> [2017-10-04 17:41:39 +0200]:
> Simplify the error handling of the SSCH and RSCH handler avoiding
> arbitrary and cryptic error codes being used to tell how the instruction
> is supposed to end. Let the code detecting the condition tell how it's
> to be handled in a less ambiguous way. It's best to handle SSCH and RSCH
> in one go as the emulation of the two shares a lot of code.
>
> For passthrough this change isn't pure refactoring, but changes the
> way kernel reported EFAULT is handled. After clarifying the kernel
> interface we decided that EFAULT shall be mapped to unit exception.
> Same goes for unexpected error codes.
>
> Signed-off-by: Halil Pasic <address@hidden>
> ---
>
> AFAIR we decided in the previous round to rather do transformation
> and fixing in one patch than touch stuff twice. Hence this patch
> ain't pure transformation any more.
> ---
> hw/s390x/css.c | 83
> +++++++++++++--------------------------------
> hw/s390x/s390-ccw.c | 11 +++---
> hw/vfio/ccw.c | 30 ++++++++++++----
> include/hw/s390x/css.h | 24 +++++++++----
> include/hw/s390x/s390-ccw.h | 2 +-
> target/s390x/ioinst.c | 53 ++++-------------------------
> 6 files changed, 77 insertions(+), 126 deletions(-)
>
> diff --git a/hw/s390x/css.c b/hw/s390x/css.c
> index 4f47dbc8b0..b2978c3bae 100644
> --- a/hw/s390x/css.c
> +++ b/hw/s390x/css.c
> @@ -1003,12 +1003,11 @@ static void sch_handle_start_func_virtual(SubchDev
> *sch)
>
> }
>
> -static int sch_handle_start_func_passthrough(SubchDev *sch)
> +static IOInstEnding sch_handle_start_func_passthrough(SubchDev *sch)
> {
>
> PMCW *p = &sch->curr_status.pmcw;
> SCSW *s = &sch->curr_status.scsw;
> - int ret;
>
> ORB *orb = &sch->orb;
> if (!(s->ctrl & SCSW_ACTL_SUSP)) {
> @@ -1022,31 +1021,11 @@ static int sch_handle_start_func_passthrough(SubchDev
> *sch)
> */
> if (!(orb->ctrl0 & ORB_CTRL0_MASK_PFCH) ||
> !(orb->ctrl0 & ORB_CTRL0_MASK_C64)) {
> - return -EINVAL;
> + sch_gen_unit_exception(sch);
> + css_inject_io_interrupt(sch);
> + return (IOInstEnding){.cc = 0};
This behavior change is not mentioned in the commit message. Right?
[...]
> diff --git a/hw/vfio/ccw.c b/hw/vfio/ccw.c
> index a8baadf57a..dbb5b201de 100644
> --- a/hw/vfio/ccw.c
> +++ b/hw/vfio/ccw.c
> @@ -23,6 +23,7 @@
> #include "hw/s390x/s390-ccw.h"
> #include "hw/s390x/ccw-device.h"
> #include "qemu/error-report.h"
> +#include "cpu.h"
We need this because?
>
> #define TYPE_VFIO_CCW "vfio-ccw"
> typedef struct VFIOCCWDevice {
> @@ -47,9 +48,9 @@ struct VFIODeviceOps vfio_ccw_ops = {
> .vfio_compute_needs_reset = vfio_ccw_compute_needs_reset,
> };
>
> -static int vfio_ccw_handle_request(ORB *orb, SCSW *scsw, void *data)
> +static IOInstEnding vfio_ccw_handle_request(SubchDev *sch)
> {
> - S390CCWDevice *cdev = data;
> + S390CCWDevice *cdev = sch->driver_data;
> VFIOCCWDevice *vcdev = DO_UPCAST(VFIOCCWDevice, cdev, cdev);
> struct ccw_io_region *region = vcdev->io_region;
> int ret;
> @@ -60,8 +61,8 @@ static int vfio_ccw_handle_request(ORB *orb, SCSW *scsw,
> void *data)
>
> memset(region, 0, sizeof(*region));
>
> - memcpy(region->orb_area, orb, sizeof(ORB));
> - memcpy(region->scsw_area, scsw, sizeof(SCSW));
> + memcpy(region->orb_area, &sch->orb, sizeof(ORB));
> + memcpy(region->scsw_area, &sch->curr_status.scsw, sizeof(SCSW));
>
> again:
> ret = pwrite(vcdev->vdev.fd, region,
> @@ -71,10 +72,25 @@ again:
> goto again;
> }
> error_report("vfio-ccw: wirte I/O region failed with errno=%d",
> errno);
> - return -errno;
> + ret = -errno;
> + } else {
> + ret = region->ret_code;
> + }
> + switch (-ret) {
> + /* Currently we don't update control block and just return the cc code.
> */
This is not true anymore? At least for the EFAULT case.
> + case 0:
> + return (IOInstEnding){.cc = 0};
> + case EBUSY:
> + return (IOInstEnding){.cc = 2};
> + case ENODEV:
> + case EACCES:
> + return (IOInstEnding){.cc = 3};
> + case EFAULT:
> + default:
> + sch_gen_unit_exception(sch);
> + css_inject_io_interrupt(sch);
> + return (IOInstEnding){.cc = 0};
> }
> -
> - return region->ret_code;
> }
>
> static void vfio_ccw_reset(DeviceState *dev)
> diff --git a/include/hw/s390x/css.h b/include/hw/s390x/css.h
> index 66916b6546..2116c6b3c7 100644
> --- a/include/hw/s390x/css.h
> +++ b/include/hw/s390x/css.h
[...]
> @@ -197,13 +208,14 @@ SubchDev *css_find_subch(uint8_t m, uint8_t cssid,
> uint8_t ssid,
> uint16_t schid);
> bool css_subch_visible(SubchDev *sch);
> void css_conditional_io_interrupt(SubchDev *sch);
> +
Extra change.
> int css_do_stsch(SubchDev *sch, SCHIB *schib);
> bool css_schid_final(int m, uint8_t cssid, uint8_t ssid, uint16_t schid);
> int css_do_msch(SubchDev *sch, const SCHIB *schib);
[...]
--
Dong Jia Shi
Re: [Qemu-devel] [PATCH v2 3/8] s390x: improve error handling for SSCH and RSCH,
Dong Jia Shi <=
[Qemu-devel] [PATCH v2 5/8] s390x: refactor error handling for CSCH handler, Halil Pasic, 2017/10/04
[Qemu-devel] [PATCH v2 2/8] s390x/css: IO instr handler ending control, Halil Pasic, 2017/10/04
- Re: [Qemu-devel] [PATCH v2 2/8] s390x/css: IO instr handler ending control, Thomas Huth, 2017/10/09
- Re: [Qemu-devel] [PATCH v2 2/8] s390x/css: IO instr handler ending control, Halil Pasic, 2017/10/09
- Re: [Qemu-devel] [PATCH v2 2/8] s390x/css: IO instr handler ending control, Thomas Huth, 2017/10/09
- Re: [Qemu-devel] [PATCH v2 2/8] s390x/css: IO instr handler ending control, Halil Pasic, 2017/10/09
- Re: [Qemu-devel] [PATCH v2 2/8] s390x/css: IO instr handler ending control, Thomas Huth, 2017/10/10
- Re: [Qemu-devel] [PATCH v2 2/8] s390x/css: IO instr handler ending control, Cornelia Huck, 2017/10/10