From 8f43710543ef305904c18072d14ace43c74b7743 Mon Sep 17 00:00:00 2001 From: Boqun Feng Date: Wed, 16 Sep 2020 11:48:17 +0800 Subject: [PATCH] scsi: storvsc: Support PAGE_SIZE larger than 4K Hyper-V always use 4k page size (HV_HYP_PAGE_SIZE), so when communicating with Hyper-V, a guest should always use HV_HYP_PAGE_SIZE as the unit for page related data. For storvsc, the data is vmbus_packet_mpb_array. And since in scsi_cmnd, sglist of pages (in unit of PAGE_SIZE) is used, we need convert pages in the sglist of scsi_cmnd into Hyper-V pages in vmbus_packet_mpb_array. This patch does the conversion by dividing pages in sglist into Hyper-V pages, offset and indexes in vmbus_packet_mpb_array are recalculated accordingly. Signed-off-by: Boqun Feng Reviewed-by: Michael Kelley Link: https://lore.kernel.org/r/20200916034817.30282-12-boqun.feng@gmail.com Signed-off-by: Wei Liu --- drivers/scsi/storvsc_drv.c | 56 +++++++++++++++++++++++++++++++++----- 1 file changed, 49 insertions(+), 7 deletions(-) diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c index 8f5f5dc863a4..0c65fbd41035 100644 --- a/drivers/scsi/storvsc_drv.c +++ b/drivers/scsi/storvsc_drv.c @@ -1739,23 +1739,65 @@ static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd) payload_sz = sizeof(cmd_request->mpb); if (sg_count) { - if (sg_count > MAX_PAGE_BUFFER_COUNT) { + unsigned int hvpgoff = 0; + unsigned long offset_in_hvpg = sgl->offset & ~HV_HYP_PAGE_MASK; + unsigned int hvpg_count = HVPFN_UP(offset_in_hvpg + length); + u64 hvpfn; - payload_sz = (sg_count * sizeof(u64) + + if (hvpg_count > MAX_PAGE_BUFFER_COUNT) { + + payload_sz = (hvpg_count * sizeof(u64) + sizeof(struct vmbus_packet_mpb_array)); payload = kzalloc(payload_sz, GFP_ATOMIC); if (!payload) return SCSI_MLQUEUE_DEVICE_BUSY; } + /* + * sgl is a list of PAGEs, and payload->range.pfn_array + * expects the page number in the unit of HV_HYP_PAGE_SIZE (the + * page size that Hyper-V uses, so here we need to divide PAGEs + * into HV_HYP_PAGE in case that PAGE_SIZE > HV_HYP_PAGE_SIZE. + * Besides, payload->range.offset should be the offset in one + * HV_HYP_PAGE. + */ payload->range.len = length; - payload->range.offset = sgl[0].offset; + payload->range.offset = offset_in_hvpg; + hvpgoff = sgl->offset >> HV_HYP_PAGE_SHIFT; cur_sgl = sgl; - for (i = 0; i < sg_count; i++) { - payload->range.pfn_array[i] = - page_to_pfn(sg_page((cur_sgl))); - cur_sgl = sg_next(cur_sgl); + for (i = 0; i < hvpg_count; i++) { + /* + * 'i' is the index of hv pages in the payload and + * 'hvpgoff' is the offset (in hv pages) of the first + * hv page in the the first page. The relationship + * between the sum of 'i' and 'hvpgoff' and the offset + * (in hv pages) in a payload page ('hvpgoff_in_page') + * is as follow: + * + * |------------------ PAGE -------------------| + * | NR_HV_HYP_PAGES_IN_PAGE hvpgs in total | + * |hvpg|hvpg| ... |hvpg|... |hvpg| + * ^ ^ ^ ^ + * +-hvpgoff-+ +-hvpgoff_in_page-+ + * ^ | + * +--------------------- i ---------------------------+ + */ + unsigned int hvpgoff_in_page = + (i + hvpgoff) % NR_HV_HYP_PAGES_IN_PAGE; + + /* + * Two cases that we need to fetch a page: + * 1) i == 0, the first step or + * 2) hvpgoff_in_page == 0, when we reach the boundary + * of a page. + */ + if (hvpgoff_in_page == 0 || i == 0) { + hvpfn = page_to_hvpfn(sg_page(cur_sgl)); + cur_sgl = sg_next(cur_sgl); + } + + payload->range.pfn_array[i] = hvpfn + hvpgoff_in_page; } }