From patchwork Fri Jun 5 11:59:29 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jan Beulich X-Patchwork-Id: 481188 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 920C61401DA for ; Fri, 5 Jun 2015 22:11:52 +1000 (AEST) Received: from localhost ([::1]:46967 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z0qTW-0005GU-FS for incoming@patchwork.ozlabs.org; Fri, 05 Jun 2015 08:11:50 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:39680) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z0qHf-00039T-3b for qemu-devel@nongnu.org; Fri, 05 Jun 2015 07:59:36 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Z0qHb-0002Yf-P6 for qemu-devel@nongnu.org; Fri, 05 Jun 2015 07:59:35 -0400 Received: from mail.emea.novell.com ([130.57.118.101]:41530) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z0qHb-0002YJ-6u for qemu-devel@nongnu.org; Fri, 05 Jun 2015 07:59:31 -0400 Received: from EMEA1-MTA by mail.emea.novell.com with Novell_GroupWise; Fri, 05 Jun 2015 12:59:30 +0100 Message-Id: <5571AB41020000780008153F@mail.emea.novell.com> X-Mailer: Novell GroupWise Internet Agent 14.0.1 Date: Fri, 05 Jun 2015 12:59:29 +0100 From: "Jan Beulich" To: References: <5571AA3B020000780008152E@mail.emea.novell.com> In-Reply-To: <5571AA3B020000780008152E@mail.emea.novell.com> Mime-Version: 1.0 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 130.57.118.101 Cc: xen-devel , Stefano Stabellini Subject: [Qemu-devel] [PATCH 1/6] xen/MSI-X: latch MSI-X table writes X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org The remaining log message in pci_msix_write() is wrong, as there guest behavior may only appear to be wrong: For one, the old logic didn't take the mask-all bit into account. And then this shouldn't depend on host device state (i.e. the host may have masked the entry without the guest having done so). Plus these writes shouldn't be dropped even when an entry gets unmasked. Instead, if they can't be made take effect right away, they should take effect on the next unmasking or enabling operation - the specification explicitly describes such caching behavior. Signed-off-by: Jan Beulich xen/MSI-X: latch MSI-X table writes The remaining log message in pci_msix_write() is wrong, as there guest behavior may only appear to be wrong: For one, the old logic didn't take the mask-all bit into account. And then this shouldn't depend on host device state (i.e. the host may have masked the entry without the guest having done so). Plus these writes shouldn't be dropped even when an entry gets unmasked. Instead, if they can't be made take effect right away, they should take effect on the next unmasking or enabling operation - the specification explicitly describes such caching behavior. Signed-off-by: Jan Beulich --- a/qemu/upstream/hw/xen/xen_pt.h +++ b/qemu/upstream/hw/xen/xen_pt.h @@ -175,9 +175,8 @@ typedef struct XenPTMSIXEntry { int pirq; uint64_t addr; uint32_t data; - uint32_t vector_ctrl; + uint32_t latch[4]; bool updated; /* indicate whether MSI ADDR or DATA is updated */ - bool warned; /* avoid issuing (bogus) warning more than once */ } XenPTMSIXEntry; typedef struct XenPTMSIX { uint32_t ctrl_offset; --- a/qemu/upstream/hw/xen/xen_pt_msi.c +++ b/qemu/upstream/hw/xen/xen_pt_msi.c @@ -25,6 +25,7 @@ #define XEN_PT_GFLAGSSHIFT_DELIV_MODE 12 #define XEN_PT_GFLAGSSHIFT_TRG_MODE 15 +#define latch(fld) latch[PCI_MSIX_ENTRY_##fld / sizeof(uint32_t)] /* * Helpers @@ -322,6 +323,13 @@ static int xen_pt_msix_update_one(XenPCI pirq = entry->pirq; + if (pirq == XEN_PT_UNASSIGNED_PIRQ || s->msix->maskall || + (entry->latch(VECTOR_CTRL) & PCI_MSIX_ENTRY_CTRL_MASKBIT)) { + entry->addr = entry->latch(LOWER_ADDR) | + ((uint64_t)entry->latch(UPPER_ADDR) << 32); + entry->data = entry->latch(DATA); + } + rc = msi_msix_setup(s, entry->addr, entry->data, &pirq, true, entry_nr, entry->pirq == XEN_PT_UNASSIGNED_PIRQ); if (rc) { @@ -396,35 +404,15 @@ int xen_pt_msix_update_remap(XenPCIPasst static uint32_t get_entry_value(XenPTMSIXEntry *e, int offset) { - switch (offset) { - case PCI_MSIX_ENTRY_LOWER_ADDR: - return e->addr & UINT32_MAX; - case PCI_MSIX_ENTRY_UPPER_ADDR: - return e->addr >> 32; - case PCI_MSIX_ENTRY_DATA: - return e->data; - case PCI_MSIX_ENTRY_VECTOR_CTRL: - return e->vector_ctrl; - default: - return 0; - } + return !(offset % sizeof(*e->latch)) + ? e->latch[offset / sizeof(*e->latch)] : 0; } static void set_entry_value(XenPTMSIXEntry *e, int offset, uint32_t val) { - switch (offset) { - case PCI_MSIX_ENTRY_LOWER_ADDR: - e->addr = (e->addr & ((uint64_t)UINT32_MAX << 32)) | val; - break; - case PCI_MSIX_ENTRY_UPPER_ADDR: - e->addr = (uint64_t)val << 32 | (e->addr & UINT32_MAX); - break; - case PCI_MSIX_ENTRY_DATA: - e->data = val; - break; - case PCI_MSIX_ENTRY_VECTOR_CTRL: - e->vector_ctrl = val; - break; + if (!(offset % sizeof(*e->latch))) + { + e->latch[offset / sizeof(*e->latch)] = val; } } @@ -444,39 +432,28 @@ static void pci_msix_write(void *opaque, offset = addr % PCI_MSIX_ENTRY_SIZE; if (offset != PCI_MSIX_ENTRY_VECTOR_CTRL) { - const volatile uint32_t *vec_ctrl; - if (get_entry_value(entry, offset) == val && entry->pirq != XEN_PT_UNASSIGNED_PIRQ) { return; } + entry->updated = true; + } else if (msix->enabled && entry->updated && + !(val & PCI_MSIX_ENTRY_CTRL_MASKBIT)) { + const volatile uint32_t *vec_ctrl; + /* * If Xen intercepts the mask bit access, entry->vec_ctrl may not be * up-to-date. Read from hardware directly. */ vec_ctrl = s->msix->phys_iomem_base + entry_nr * PCI_MSIX_ENTRY_SIZE + PCI_MSIX_ENTRY_VECTOR_CTRL; + set_entry_value(entry, offset, *vec_ctrl); - if (msix->enabled && !(*vec_ctrl & PCI_MSIX_ENTRY_CTRL_MASKBIT)) { - if (!entry->warned) { - entry->warned = true; - XEN_PT_ERR(&s->dev, "Can't update msix entry %d since MSI-X is" - " already enabled.\n", entry_nr); - } - return; - } - - entry->updated = true; + xen_pt_msix_update_one(s, entry_nr); } set_entry_value(entry, offset, val); - - if (offset == PCI_MSIX_ENTRY_VECTOR_CTRL) { - if (msix->enabled && !(val & PCI_MSIX_ENTRY_CTRL_MASKBIT)) { - xen_pt_msix_update_one(s, entry_nr); - } - } } static uint64_t pci_msix_read(void *opaque, hwaddr addr, --- a/qemu/upstream/hw/xen/xen_pt.h +++ b/qemu/upstream/hw/xen/xen_pt.h @@ -175,9 +175,8 @@ typedef struct XenPTMSIXEntry { int pirq; uint64_t addr; uint32_t data; - uint32_t vector_ctrl; + uint32_t latch[4]; bool updated; /* indicate whether MSI ADDR or DATA is updated */ - bool warned; /* avoid issuing (bogus) warning more than once */ } XenPTMSIXEntry; typedef struct XenPTMSIX { uint32_t ctrl_offset; --- a/qemu/upstream/hw/xen/xen_pt_msi.c +++ b/qemu/upstream/hw/xen/xen_pt_msi.c @@ -25,6 +25,7 @@ #define XEN_PT_GFLAGSSHIFT_DELIV_MODE 12 #define XEN_PT_GFLAGSSHIFT_TRG_MODE 15 +#define latch(fld) latch[PCI_MSIX_ENTRY_##fld / sizeof(uint32_t)] /* * Helpers @@ -322,6 +323,13 @@ static int xen_pt_msix_update_one(XenPCI pirq = entry->pirq; + if (pirq == XEN_PT_UNASSIGNED_PIRQ || s->msix->maskall || + (entry->latch(VECTOR_CTRL) & PCI_MSIX_ENTRY_CTRL_MASKBIT)) { + entry->addr = entry->latch(LOWER_ADDR) | + ((uint64_t)entry->latch(UPPER_ADDR) << 32); + entry->data = entry->latch(DATA); + } + rc = msi_msix_setup(s, entry->addr, entry->data, &pirq, true, entry_nr, entry->pirq == XEN_PT_UNASSIGNED_PIRQ); if (rc) { @@ -396,35 +404,15 @@ int xen_pt_msix_update_remap(XenPCIPasst static uint32_t get_entry_value(XenPTMSIXEntry *e, int offset) { - switch (offset) { - case PCI_MSIX_ENTRY_LOWER_ADDR: - return e->addr & UINT32_MAX; - case PCI_MSIX_ENTRY_UPPER_ADDR: - return e->addr >> 32; - case PCI_MSIX_ENTRY_DATA: - return e->data; - case PCI_MSIX_ENTRY_VECTOR_CTRL: - return e->vector_ctrl; - default: - return 0; - } + return !(offset % sizeof(*e->latch)) + ? e->latch[offset / sizeof(*e->latch)] : 0; } static void set_entry_value(XenPTMSIXEntry *e, int offset, uint32_t val) { - switch (offset) { - case PCI_MSIX_ENTRY_LOWER_ADDR: - e->addr = (e->addr & ((uint64_t)UINT32_MAX << 32)) | val; - break; - case PCI_MSIX_ENTRY_UPPER_ADDR: - e->addr = (uint64_t)val << 32 | (e->addr & UINT32_MAX); - break; - case PCI_MSIX_ENTRY_DATA: - e->data = val; - break; - case PCI_MSIX_ENTRY_VECTOR_CTRL: - e->vector_ctrl = val; - break; + if (!(offset % sizeof(*e->latch))) + { + e->latch[offset / sizeof(*e->latch)] = val; } } @@ -444,39 +432,28 @@ static void pci_msix_write(void *opaque, offset = addr % PCI_MSIX_ENTRY_SIZE; if (offset != PCI_MSIX_ENTRY_VECTOR_CTRL) { - const volatile uint32_t *vec_ctrl; - if (get_entry_value(entry, offset) == val && entry->pirq != XEN_PT_UNASSIGNED_PIRQ) { return; } + entry->updated = true; + } else if (msix->enabled && entry->updated && + !(val & PCI_MSIX_ENTRY_CTRL_MASKBIT)) { + const volatile uint32_t *vec_ctrl; + /* * If Xen intercepts the mask bit access, entry->vec_ctrl may not be * up-to-date. Read from hardware directly. */ vec_ctrl = s->msix->phys_iomem_base + entry_nr * PCI_MSIX_ENTRY_SIZE + PCI_MSIX_ENTRY_VECTOR_CTRL; + set_entry_value(entry, offset, *vec_ctrl); - if (msix->enabled && !(*vec_ctrl & PCI_MSIX_ENTRY_CTRL_MASKBIT)) { - if (!entry->warned) { - entry->warned = true; - XEN_PT_ERR(&s->dev, "Can't update msix entry %d since MSI-X is" - " already enabled.\n", entry_nr); - } - return; - } - - entry->updated = true; + xen_pt_msix_update_one(s, entry_nr); } set_entry_value(entry, offset, val); - - if (offset == PCI_MSIX_ENTRY_VECTOR_CTRL) { - if (msix->enabled && !(val & PCI_MSIX_ENTRY_CTRL_MASKBIT)) { - xen_pt_msix_update_one(s, entry_nr); - } - } } static uint64_t pci_msix_read(void *opaque, hwaddr addr,