From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Halil Pasic Subject: [RFC PATCH 12/12] virtio/s390: make airq summary indicators DMA Date: Fri, 5 Apr 2019 01:16:22 +0200 In-Reply-To: <20190404231622.52531-1-pasic@linux.ibm.com> References: <20190404231622.52531-1-pasic@linux.ibm.com> Message-Id: <20190404231622.52531-13-pasic@linux.ibm.com> Sender: kvm-owner@vger.kernel.org List-Archive: List-Post: To: kvm@vger.kernel.org, linux-s390@vger.kernel.org, Cornelia Huck , Martin Schwidefsky , Sebastian Ott Cc: Halil Pasic , virtualization@lists.linux-foundation.org, Christian Borntraeger , Viktor Mihajlovski , Vasily Gorbik , Janosch Frank , Claudio Imbrenda , Farhan Ali , Eric Farman List-ID: Hypervisor needs to interact with the summary indicators, so these need to be DMA memory as well (at least for protected virtualization guests). Signed-off-by: Halil Pasic --- drivers/s390/virtio/virtio_ccw.c | 24 +++++++++++++++++------- 1 file changed, 17 insertions(+), 7 deletions(-) diff --git a/drivers/s390/virtio/virtio_ccw.c b/drivers/s390/virtio/virtio_ccw.c index ba1dafe04968..5ef82461d0f2 100644 --- a/drivers/s390/virtio/virtio_ccw.c +++ b/drivers/s390/virtio/virtio_ccw.c @@ -141,11 +141,17 @@ static int virtio_ccw_use_airq = 1; struct airq_info { rwlock_t lock; - u8 summary_indicator; + u8 summary_indicator_idx; struct airq_struct airq; struct airq_iv *aiv; }; static struct airq_info *airq_areas[MAX_AIRQ_AREAS]; +static u8 *summary_indicators; + +static inline u8 *get_summary_indicator(struct airq_info *info) +{ + return summary_indicators + info->summary_indicator_idx; +} #define CCW_CMD_SET_VQ 0x13 #define CCW_CMD_VDEV_RESET 0x33 @@ -229,7 +235,7 @@ static void virtio_airq_handler(struct airq_struct *airq) break; vring_interrupt(0, (void *)airq_iv_get_ptr(info->aiv, ai)); } - info->summary_indicator = 0; + *(get_summary_indicator(info)) = 0; smp_wmb(); /* Walk through indicators field, summary indicator not active. */ for (ai = 0;;) { @@ -241,7 +247,8 @@ static void virtio_airq_handler(struct airq_struct *airq) read_unlock(&info->lock); } -static struct airq_info *new_airq_info(void) +/* call with airq_areas_lock held */ +static struct airq_info *new_airq_info(int index) { struct airq_info *info; int rc; @@ -256,7 +263,8 @@ static struct airq_info *new_airq_info(void) return NULL; } info->airq.handler = virtio_airq_handler; - info->airq.lsi_ptr = &info->summary_indicator; + info->summary_indicator_idx = index; + info->airq.lsi_ptr = get_summary_indicator(info); info->airq.lsi_mask = 0xff; info->airq.isc = VIRTIO_AIRQ_ISC; rc = register_adapter_interrupt(&info->airq); @@ -277,8 +285,9 @@ static unsigned long get_airq_indicator(struct virtqueue *vqs[], int nvqs, unsigned long bit, flags; for (i = 0; i < MAX_AIRQ_AREAS && !indicator_addr; i++) { + /* TODO: this seems to be racy */ if (!airq_areas[i]) - airq_areas[i] = new_airq_info(); + airq_areas[i] = new_airq_info(i); info = airq_areas[i]; if (!info) return 0; @@ -363,7 +372,7 @@ static void virtio_ccw_drop_indicator(struct virtio_ccw_device *vcdev, if (!thinint_area) return; thinint_area->summary_indicator = - (unsigned long) &airq_info->summary_indicator; + (unsigned long) get_summary_indicator(airq_info); thinint_area->isc = VIRTIO_AIRQ_ISC; ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER; ccw->count = sizeof(*thinint_area); @@ -626,7 +635,7 @@ static int virtio_ccw_register_adapter_ind(struct virtio_ccw_device *vcdev, } info = vcdev->airq_info; thinint_area->summary_indicator = - (unsigned long) &info->summary_indicator; + (unsigned long) get_summary_indicator(info); thinint_area->isc = VIRTIO_AIRQ_ISC; ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER; ccw->flags = CCW_FLAG_SLI; @@ -1515,6 +1524,7 @@ static int __init virtio_ccw_init(void) { /* parse no_auto string before we do anything further */ no_auto_parse(); + summary_indicators = cio_dma_zalloc(MAX_AIRQ_AREAS); return ccw_driver_register(&virtio_ccw_driver); } device_initcall(virtio_ccw_init); -- 2.16.4