Qing He
2009-Feb-16 08:44 UTC
[Xen-devel] [PATCH] passthrough: fix MSI-X table fixmap allocation
Currently, msix table pages are allocated a fixmap page per vector,
the available fixmap pages will be depleted when assigning devices with
large number of vectors. This patch fixes it, and a bug that prevents
cross-page MSI-X table from working properly
Signed-off-by: Qing He <qing.he@intel.com>
---
arch/x86/msi.c | 109 +++++++++++++++++++++++++++++++++-------------
drivers/passthrough/pci.c | 1
include/asm-x86/fixmap.h | 2
include/asm-x86/msi.h | 6 +-
include/xen/pci.h | 6 ++
5 files changed, 90 insertions(+), 34 deletions(-)
diff -r c3b5e36248c9 xen/arch/x86/msi.c
--- a/xen/arch/x86/msi.c Tue Feb 03 18:14:19 2009 +0000
+++ b/xen/arch/x86/msi.c Wed Feb 04 14:41:03 2009 +0800
@@ -29,17 +29,17 @@
/* bitmap indicate which fixed map is free */
DEFINE_SPINLOCK(msix_fixmap_lock);
-DECLARE_BITMAP(msix_fixmap_pages, MAX_MSIX_PAGES);
+DECLARE_BITMAP(msix_fixmap_pages, FIX_MSIX_MAX_PAGES);
static int msix_fixmap_alloc(void)
{
- int i, rc = -1;
+ int i, rc = -ENOMEM;
spin_lock(&msix_fixmap_lock);
- for ( i = 0; i < MAX_MSIX_PAGES; i++ )
+ for ( i = 0; i < FIX_MSIX_MAX_PAGES; i++ )
if ( !test_bit(i, &msix_fixmap_pages) )
break;
- if ( i == MAX_MSIX_PAGES )
+ if ( i == FIX_MSIX_MAX_PAGES )
goto out;
rc = FIX_MSIX_IO_RESERV_BASE + i;
set_bit(i, &msix_fixmap_pages);
@@ -51,8 +51,66 @@ static int msix_fixmap_alloc(void)
static void msix_fixmap_free(int idx)
{
+ spin_lock(&msix_fixmap_lock);
if ( idx >= FIX_MSIX_IO_RESERV_BASE )
clear_bit(idx - FIX_MSIX_IO_RESERV_BASE, &msix_fixmap_pages);
+ spin_unlock(&msix_fixmap_lock);
+}
+
+static int msix_get_fixmap(struct pci_dev *dev, unsigned long table_paddr,
+ unsigned long entry_paddr)
+{
+ int nr_page, idx;
+
+ nr_page = (entry_paddr >> PAGE_SHIFT) - (table_paddr >>
PAGE_SHIFT);
+
+ if ( nr_page < 0 || nr_page >= MAX_MSIX_TABLE_PAGES )
+ return -EINVAL;
+
+ spin_lock(&dev->msix_table_lock);
+ if ( dev->msix_table_refcnt[nr_page]++ == 0 )
+ {
+ idx = msix_fixmap_alloc();
+ if ( idx < 0 )
+ {
+ dev->msix_table_refcnt[nr_page]--;
+ goto out;
+ }
+ set_fixmap_nocache(idx, entry_paddr);
+ dev->msix_table_idx[nr_page] = idx;
+ }
+ else
+ idx = dev->msix_table_idx[nr_page];
+
+ out:
+ spin_unlock(&dev->msix_table_lock);
+ return idx;
+}
+
+static void msix_put_fixmap(struct pci_dev *dev, int idx)
+{
+ int i;
+ unsigned long start;
+
+ spin_lock(&dev->msix_table_lock);
+ for ( i = 0; i < MAX_MSIX_TABLE_PAGES; i++ )
+ {
+ if ( dev->msix_table_idx[i] == idx )
+ break;
+ }
+ if ( i == MAX_MSIX_TABLE_PAGES )
+ goto out;
+
+ if ( --dev->msix_table_refcnt[i] == 0 )
+ {
+ start = fix_to_virt(idx);
+ destroy_xen_mappings(start, start + PAGE_SIZE);
+ msix_fixmap_free(idx);
+ dev->msix_table_idx[i] = 0;
+ }
+
+ out:
+ spin_unlock(&dev->msix_table_lock);
}
/*
@@ -122,8 +180,7 @@ static void read_msi_msg(struct msi_desc
case PCI_CAP_ID_MSIX:
{
void __iomem *base;
- base = entry->mask_base +
- entry->msi_attrib.entry_nr * PCI_MSIX_ENTRY_SIZE;
+ base = entry->mask_base;
msg->address_lo = readl(base + PCI_MSIX_ENTRY_LOWER_ADDR_OFFSET);
msg->address_hi = readl(base + PCI_MSIX_ENTRY_UPPER_ADDR_OFFSET);
@@ -199,8 +256,7 @@ static void write_msi_msg(struct msi_des
case PCI_CAP_ID_MSIX:
{
void __iomem *base;
- base = entry->mask_base +
- entry->msi_attrib.entry_nr * PCI_MSIX_ENTRY_SIZE;
+ base = entry->mask_base;
writel(msg->address_lo,
base + PCI_MSIX_ENTRY_LOWER_ADDR_OFFSET);
@@ -288,8 +344,7 @@ static void msix_flush_writes(unsigned i
break;
case PCI_CAP_ID_MSIX:
{
- int offset = entry->msi_attrib.entry_nr * PCI_MSIX_ENTRY_SIZE +
- PCI_MSIX_ENTRY_VECTOR_CTRL_OFFSET;
+ int offset = PCI_MSIX_ENTRY_VECTOR_CTRL_OFFSET;
readl(entry->mask_base + offset);
break;
}
@@ -330,8 +385,7 @@ static void msi_set_mask_bit(unsigned in
break;
case PCI_CAP_ID_MSIX:
{
- int offset = entry->msi_attrib.entry_nr * PCI_MSIX_ENTRY_SIZE +
- PCI_MSIX_ENTRY_VECTOR_CTRL_OFFSET;
+ int offset = PCI_MSIX_ENTRY_VECTOR_CTRL_OFFSET;
writel(flag, entry->mask_base + offset);
readl(entry->mask_base + offset);
break;
@@ -392,13 +446,10 @@ int msi_free_vector(struct msi_desc *ent
{
unsigned long start;
- writel(1, entry->mask_base + entry->msi_attrib.entry_nr
- * PCI_MSIX_ENTRY_SIZE
- + PCI_MSIX_ENTRY_VECTOR_CTRL_OFFSET);
+ writel(1, entry->mask_base + PCI_MSIX_ENTRY_VECTOR_CTRL_OFFSET);
start = (unsigned long)entry->mask_base & ~(PAGE_SIZE - 1);
- msix_fixmap_free(virt_to_fix(start));
- destroy_xen_mappings(start, start + PAGE_SIZE);
+ msix_put_fixmap(entry->dev, virt_to_fix(start));
}
list_del(&entry->list);
xfree(entry);
@@ -500,8 +551,8 @@ static int msix_capability_init(struct p
struct msi_desc *entry;
int pos;
u16 control;
- unsigned long phys_addr;
- u32 table_offset;
+ unsigned long table_paddr, entry_paddr;
+ u32 table_offset, entry_offset;
u8 bir;
void __iomem *base;
int idx;
@@ -525,15 +576,17 @@ static int msix_capability_init(struct p
table_offset = pci_conf_read32(bus, slot, func,
msix_table_offset_reg(pos));
bir = (u8)(table_offset & PCI_MSIX_FLAGS_BIRMASK);
table_offset &= ~PCI_MSIX_FLAGS_BIRMASK;
- phys_addr = msi->table_base + table_offset;
- idx = msix_fixmap_alloc();
+ entry_offset = msi->entry_nr * PCI_MSIX_ENTRY_SIZE;
+
+ table_paddr = msi->table_base + table_offset;
+ entry_paddr = table_paddr + entry_offset;
+ idx = msix_get_fixmap(dev, table_paddr, entry_paddr);
if ( idx < 0 )
{
xfree(entry);
- return -ENOMEM;
+ return idx;
}
- set_fixmap_nocache(idx, phys_addr);
- base = (void *)(fix_to_virt(idx) + (phys_addr & ((1UL <<
PAGE_SHIFT) - 1)));
+ base = (void *)(fix_to_virt(idx) + (entry_paddr & ((1UL <<
PAGE_SHIFT) - 1)));
entry->msi_attrib.type = PCI_CAP_ID_MSIX;
entry->msi_attrib.is_64 = 1;
@@ -548,9 +601,7 @@ static int msix_capability_init(struct p
list_add_tail(&entry->list, &dev->msi_list);
/* Mask interrupt here */
- writel(1, entry->mask_base + entry->msi_attrib.entry_nr
- * PCI_MSIX_ENTRY_SIZE
- + PCI_MSIX_ENTRY_VECTOR_CTRL_OFFSET);
+ writel(1, entry->mask_base + PCI_MSIX_ENTRY_VECTOR_CTRL_OFFSET);
*desc = entry;
/* Restore MSI-X enabled bits */
@@ -675,9 +726,7 @@ static void __pci_disable_msix(struct ms
BUG_ON(list_empty(&dev->msi_list));
- writel(1, entry->mask_base + entry->msi_attrib.entry_nr
- * PCI_MSIX_ENTRY_SIZE
- + PCI_MSIX_ENTRY_VECTOR_CTRL_OFFSET);
+ writel(1, entry->mask_base + PCI_MSIX_ENTRY_VECTOR_CTRL_OFFSET);
pci_conf_write16(bus, slot, func, msix_control_reg(pos), control);
}
diff -r c3b5e36248c9 xen/drivers/passthrough/pci.c
--- a/xen/drivers/passthrough/pci.c Tue Feb 03 18:14:19 2009 +0000
+++ b/xen/drivers/passthrough/pci.c Wed Feb 04 14:41:03 2009 +0800
@@ -48,6 +48,7 @@ struct pci_dev *alloc_pdev(u8 bus, u8 de
pdev->domain = NULL;
INIT_LIST_HEAD(&pdev->msi_list);
list_add(&pdev->alldevs_list, &alldevs_list);
+ spin_lock_init(&pdev->msix_table_lock);
return pdev;
}
diff -r c3b5e36248c9 xen/include/asm-x86/fixmap.h
--- a/xen/include/asm-x86/fixmap.h Tue Feb 03 18:14:19 2009 +0000
+++ b/xen/include/asm-x86/fixmap.h Wed Feb 04 14:41:03 2009 +0800
@@ -50,7 +50,7 @@ enum fixed_addresses {
FIX_IOMMU_MMIO_END = FIX_IOMMU_MMIO_BASE_0 + IOMMU_PAGES -1,
FIX_TBOOT_SHARED_BASE,
FIX_MSIX_IO_RESERV_BASE,
- FIX_MSIX_IO_RESERV_END = FIX_MSIX_IO_RESERV_BASE + MAX_MSIX_PAGES -1,
+ FIX_MSIX_IO_RESERV_END = FIX_MSIX_IO_RESERV_BASE + FIX_MSIX_MAX_PAGES -1,
__end_of_fixed_addresses
};
diff -r c3b5e36248c9 xen/include/asm-x86/msi.h
--- a/xen/include/asm-x86/msi.h Tue Feb 03 18:14:19 2009 +0000
+++ b/xen/include/asm-x86/msi.h Wed Feb 04 14:41:03 2009 +0800
@@ -49,9 +49,9 @@
/* MAX fixed pages reserved for mapping MSIX tables. */
#if defined(__x86_64__)
-#define MAX_MSIX_PAGES 512
+#define FIX_MSIX_MAX_PAGES 512
#else
-#define MAX_MSIX_PAGES 32
+#define FIX_MSIX_MAX_PAGES 32
#endif
struct msi_info {
@@ -93,7 +93,7 @@ struct msi_desc {
struct list_head list;
- void __iomem *mask_base;
+ void __iomem *mask_base; /* va for the entry in mask table */
struct pci_dev *dev;
int vector;
diff -r c3b5e36248c9 xen/include/xen/pci.h
--- a/xen/include/xen/pci.h Tue Feb 03 18:14:19 2009 +0000
+++ b/xen/include/xen/pci.h Wed Feb 04 14:41:03 2009 +0800
@@ -29,10 +29,16 @@
#define PCI_BDF(b,d,f) ((((b) & 0xff) << 8) | PCI_DEVFN(d,f))
#define PCI_BDF2(b,df) ((((b) & 0xff) << 8) | ((df) & 0xff))
+#define MAX_MSIX_TABLE_PAGES 8 /* 2048 entries */
struct pci_dev {
struct list_head alldevs_list;
struct list_head domain_list;
+
struct list_head msi_list;
+ int msix_table_refcnt[MAX_MSIX_TABLE_PAGES];
+ int msix_table_idx[MAX_MSIX_TABLE_PAGES];
+ spinlock_t msix_table_lock;
+
struct domain *domain;
const u8 bus;
const u8 devfn;
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Keir Fraser
2009-Feb-16 09:04 UTC
Re: [Xen-devel] [PATCH] passthrough: fix MSI-X table fixmap allocation
On 16/02/2009 08:44, "Qing He" <qing.he@intel.com> wrote:> Currently, msix table pages are allocated a fixmap page per vector, > the available fixmap pages will be depleted when assigning devices with > large number of vectors. This patch fixes it, and a bug that prevents > cross-page MSI-X table from working properly > > Signed-off-by: Qing He <qing.he@intel.com>How does it fix it? Just a couple of sentences please, which I''ll add to the changeset comment. -- Keir _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Qing He
2009-Feb-16 09:33 UTC
Re: [Xen-devel] [PATCH] passthrough: fix MSI-X table fixmap allocation
On Mon, 2009-02-16 at 17:04 +0800, Keir Fraser wrote:> On 16/02/2009 08:44, "Qing He" <qing.he@intel.com> wrote: > > > Currently, msix table pages are allocated a fixmap page per vector, > > the available fixmap pages will be depleted when assigning devices with > > large number of vectors. This patch fixes it, and a bug that prevents > > cross-page MSI-X table from working properly > > > > Signed-off-by: Qing He <qing.he@intel.com> > > How does it fix it? Just a couple of sentences please, which I''ll add to the > changeset comment.It now allocates msix table fixmap pages per device, if the table entries of two msix vectors share the same page, it will only be mapped to fixmap once. A ref count is maintained so that it can be unmapped when all the vectors are freed. Also changes the meaning of msi_desc->mask_base from the va of msix table start to the va of the target entry. The former one is currently bugged (it always maps the first page but msix can support up to 2048 entries) and can''t handle separately allocated pages. Thanks, Qing> > -- Keir > >_______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel