From: Stewart Hildebrand <stewart.hildebrand@amd.com>
A PCI device must have valid BARs in order to assign it to a domain. On
ARM, firmware is unlikely to have initialized the BARs, so we must do
this in Xen. During setup_hwdom_pci_devices(), check if each BAR is
valid. If the BAR happens to already be valid, remove the BAR range from
a rangeset of valid PCI ranges so as to avoid overlap when reserving a
new BAR. If not valid, reserve a new BAR address from the rangeset and
write it to the device.
Avaliable ranges are read from DT during init and stored in distinct
rangesets.
Signed-off-by: Stewart Hildebrand <stewart.hildebrand@amd.com>
Signed-off-by: Mykyta Poturai <mykyta_poturai@epam.com>
---
xen/arch/arm/include/asm/pci.h | 7 +++
xen/arch/arm/pci/pci-host-common.c | 78 +++++++++++++++++++++++++++++
xen/arch/x86/include/asm/pci.h | 14 ++++++
xen/common/rangeset.c | 35 +++++++++++++
xen/drivers/passthrough/pci.c | 79 ++++++++++++++++++++++++++++++
xen/include/xen/rangeset.h | 6 ++-
6 files changed, 218 insertions(+), 1 deletion(-)
diff --git a/xen/arch/arm/include/asm/pci.h b/xen/arch/arm/include/asm/pci.h
index 4fc46da315..ba4caa56ae 100644
--- a/xen/arch/arm/include/asm/pci.h
+++ b/xen/arch/arm/include/asm/pci.h
@@ -74,6 +74,8 @@ struct pci_host_bridge {
struct pci_config_window *child_cfg;
const struct pci_ops *child_ops;
void *priv; /* Private data of the bridge. */
+ struct rangeset *bar_ranges;
+ struct rangeset *bar_ranges_prefetch;
};
struct pci_ops {
@@ -154,6 +156,11 @@ void pci_generic_init_bus_range_child(struct dt_device_node *dev,
bool arch_pci_device_physdevop(void);
+uint64_t pci_get_new_bar_addr(const struct pci_dev *pdev, uint64_t size,
+ bool is_64bit, bool prefetch);
+int pci_reserve_bar_range(const struct pci_dev *pdev, uint64_t addr,
+ uint64_t size, bool prefetch);
+
#else /*!CONFIG_HAS_PCI*/
#define pci_scan_enabled false
diff --git a/xen/arch/arm/pci/pci-host-common.c b/xen/arch/arm/pci/pci-host-common.c
index 67447d8696..bfe610a403 100644
--- a/xen/arch/arm/pci/pci-host-common.c
+++ b/xen/arch/arm/pci/pci-host-common.c
@@ -21,6 +21,7 @@
#include <xen/rwlock.h>
#include <xen/sched.h>
#include <xen/vmap.h>
+#include <xen/resource.h>
#include <asm/setup.h>
@@ -232,6 +233,21 @@ static int pci_bus_find_domain_nr(struct dt_device_node *dev)
return domain;
}
+static int add_bar_range(const struct dt_device_node *dev, uint32_t flags,
+ uint64_t addr, uint64_t len, void *data)
+{
+ struct pci_host_bridge *bridge = data;
+
+ if ( !(flags & IORESOURCE_MEM) )
+ return 0;
+
+ if ( flags & IORESOURCE_PREFETCH )
+ return rangeset_add_range(bridge->bar_ranges_prefetch, addr,
+ addr + len - 1);
+ else
+ return rangeset_add_range(bridge->bar_ranges, addr, addr + len - 1);
+}
+
struct pci_host_bridge *
pci_host_common_probe(struct dt_device_node *dev,
const struct pci_ecam_ops *ops,
@@ -286,6 +302,14 @@ pci_host_common_probe(struct dt_device_node *dev,
pci_add_host_bridge(bridge);
pci_add_segment(bridge->segment);
+ bridge->bar_ranges = rangeset_new(NULL, "BAR ranges",
+ RANGESETF_prettyprint_hex);
+ bridge->bar_ranges_prefetch = rangeset_new(NULL,
+ "BAR ranges (prefetchable)",
+ RANGESETF_prettyprint_hex);
+ if ( bridge->bar_ranges && bridge->bar_ranges_prefetch )
+ dt_for_each_range(bridge->dt_node, add_bar_range, bridge);
+
return bridge;
err_child:
@@ -476,6 +500,60 @@ bool pci_check_bar(const struct pci_dev *pdev, mfn_t start, mfn_t end)
return bar_data.is_valid;
}
+
+uint64_t pci_get_new_bar_addr(const struct pci_dev *pdev, uint64_t size,
+ bool is_64bit, bool prefetch)
+{
+ struct pci_host_bridge *bridge;
+ struct rangeset *range;
+ uint64_t addr;
+
+ bridge = pci_find_host_bridge(pdev->seg, pdev->bus);
+ if ( !bridge )
+ return 0;
+
+ range = prefetch ? bridge->bar_ranges_prefetch : bridge->bar_ranges;
+
+ if ( size < PAGE_SIZE )
+ size = PAGE_SIZE;
+
+ if ( is_64bit && !rangeset_find_aligned_range(range, size, GB(4), &addr) )
+ {
+ if ( rangeset_remove_range(range, addr, addr + size - 1) )
+ {
+ printk("%s:%d:%s error\n", __FILE__, __LINE__, __func__);
+ }
+ return addr;
+ }
+ if ( !rangeset_find_aligned_range(range, size, 0, &addr) )
+ {
+ if ( !is_64bit && addr >= GB(4) )
+ return 0;
+ if ( rangeset_remove_range(range, addr, addr + size - 1) )
+ {
+ printk("%s:%d:%s error\n", __FILE__, __LINE__, __func__);
+ }
+ return addr;
+ }
+
+ return 0;
+}
+
+int pci_reserve_bar_range(const struct pci_dev *pdev, uint64_t addr,
+ uint64_t size, bool prefetch)
+{
+ struct pci_host_bridge *bridge;
+ struct rangeset *range;
+
+ bridge = pci_find_host_bridge(pdev->seg, pdev->bus);
+ if ( !bridge )
+ return 0;
+
+ range = prefetch ? bridge->bar_ranges_prefetch : bridge->bar_ranges;
+
+ return rangeset_remove_range(range, addr, addr + size - 1);
+}
+
/*
* Local variables:
* mode: C
diff --git a/xen/arch/x86/include/asm/pci.h b/xen/arch/x86/include/asm/pci.h
index 08e8959d0d..2cabbbb5d0 100644
--- a/xen/arch/x86/include/asm/pci.h
+++ b/xen/arch/x86/include/asm/pci.h
@@ -82,4 +82,18 @@ static inline bool hwdom_uses_vpci(void)
return false;
}
+static inline uint64_t pci_get_new_bar_addr(const struct pci_dev *pdev,
+ uint64_t size, bool is_64bit,
+ bool prefetch)
+{
+ return 0;
+}
+
+static inline int pci_reserve_bar_range(const struct pci_dev *pdev,
+ uint64_t addr, uint64_t size,
+ bool prefetch)
+{
+ return 0;
+}
+
#endif /* __X86_PCI_H__ */
diff --git a/xen/common/rangeset.c b/xen/common/rangeset.c
index 0e3b9acd35..c1c6f8610c 100644
--- a/xen/common/rangeset.c
+++ b/xen/common/rangeset.c
@@ -357,6 +357,41 @@ int rangeset_claim_range(struct rangeset *r, unsigned long size,
return 0;
}
+int rangeset_find_aligned_range(struct rangeset *r, unsigned long size,
+ unsigned long min, unsigned long *s)
+{
+ struct range *x;
+
+ /* Power of 2 check */
+ if ( (size & (size - 1)) != 0 )
+ {
+ *s = 0;
+ return -EINVAL;
+ }
+
+ read_lock(&r->lock);
+
+ for ( x = first_range(r); x; x = next_range(r, x) )
+ {
+ /* Assumes size is a power of 2 */
+ unsigned long start_aligned = (x->s + size - 1) & ~(size - 1);
+
+ if ( x->e > start_aligned &&
+ (x->e - start_aligned) >= size &&
+ start_aligned >= min )
+ {
+ read_unlock(&r->lock);
+ *s = start_aligned;
+ return 0;
+ }
+ }
+
+ read_unlock(&r->lock);
+ *s = 0;
+
+ return -ENOSPC;
+}
+
int rangeset_consume_ranges(struct rangeset *r,
int (*cb)(unsigned long s, unsigned long e,
void *ctxt, unsigned long *c),
diff --git a/xen/drivers/passthrough/pci.c b/xen/drivers/passthrough/pci.c
index 3edcfa8a04..4f5de9a542 100644
--- a/xen/drivers/passthrough/pci.c
+++ b/xen/drivers/passthrough/pci.c
@@ -1172,6 +1172,80 @@ int __init scan_pci_devices(void)
return ret;
}
+static void __init cf_check reserve_bar_range(struct pci_dev *pdev, uint8_t reg,
+ uint64_t addr, uint64_t size,
+ bool is_64bit, bool prefetch)
+{
+ if ( pci_check_bar(pdev, maddr_to_mfn(addr),
+ maddr_to_mfn(addr + size - 1)) )
+ pci_reserve_bar_range(pdev, addr, size, prefetch);
+}
+
+static void __init cf_check get_new_bar_addr(struct pci_dev *pdev, uint8_t reg,
+ uint64_t addr, uint64_t size,
+ bool is_64bit, bool prefetch)
+{
+ if ( !pci_check_bar(pdev, maddr_to_mfn(addr),
+ maddr_to_mfn(addr + size - 1)) )
+ {
+ uint16_t cmd = pci_conf_read16(pdev->sbdf, PCI_COMMAND);
+
+ addr = pci_get_new_bar_addr(pdev, size, is_64bit, prefetch);
+
+ pci_conf_write16(pdev->sbdf, PCI_COMMAND,
+ cmd & ~(PCI_COMMAND_MEMORY | PCI_COMMAND_IO));
+
+ pci_conf_write32(pdev->sbdf, reg,
+ (addr & GENMASK(31, 0)) |
+ (is_64bit ? PCI_BASE_ADDRESS_MEM_TYPE_64 : 0));
+
+ if ( is_64bit )
+ pci_conf_write32(pdev->sbdf, reg + 4, addr >> 32);
+
+ pci_conf_write16(pdev->sbdf, PCI_COMMAND, cmd);
+ }
+}
+
+static int __init cf_check bars_iterate(struct pci_seg *pseg, void *arg)
+{
+ struct pci_dev *pdev;
+ unsigned int i, ret, num_bars = PCI_HEADER_NORMAL_NR_BARS;
+ uint64_t addr, size;
+ void (*cb)(struct pci_dev *, uint8_t, uint64_t, uint64_t, bool, bool) = arg;
+
+ list_for_each_entry ( pdev, &pseg->alldevs_list, alldevs_list )
+ {
+ if ( (pci_conf_read8(pdev->sbdf, PCI_HEADER_TYPE) & 0x7f) ==
+ PCI_HEADER_TYPE_NORMAL )
+ {
+ for ( i = 0; i < num_bars; i += ret )
+ {
+ uint8_t reg = PCI_BASE_ADDRESS_0 + i * 4;
+ bool prefetch;
+
+ if ( (pci_conf_read32(pdev->sbdf, reg) & PCI_BASE_ADDRESS_SPACE)
+ == PCI_BASE_ADDRESS_SPACE_IO )
+ {
+ ret = 1;
+ continue;
+ }
+
+ ret = pci_size_mem_bar(pdev->sbdf, reg, &addr, &size,
+ (i == num_bars - 1) ? PCI_BAR_LAST : 0);
+
+ if ( !size )
+ continue;
+ prefetch = !!(pci_conf_read32(pdev->sbdf, reg) &
+ PCI_BASE_ADDRESS_MEM_PREFETCH);
+
+ cb(pdev, reg, addr, size, ret == 2, prefetch);
+ }
+ }
+ }
+
+ return 0;
+}
+
struct setup_hwdom {
struct domain *d;
int (*handler)(uint8_t devfn, struct pci_dev *pdev);
@@ -1263,6 +1337,11 @@ void __hwdom_init setup_hwdom_pci_devices(
struct setup_hwdom ctxt = { .d = d, .handler = handler };
pcidevs_lock();
+ if ( hwdom_uses_vpci() )
+ {
+ pci_segments_iterate(bars_iterate, reserve_bar_range);
+ pci_segments_iterate(bars_iterate, get_new_bar_addr);
+ }
pci_segments_iterate(_setup_hwdom_pci_devices, &ctxt);
pcidevs_unlock();
}
diff --git a/xen/include/xen/rangeset.h b/xen/include/xen/rangeset.h
index 817505badf..e71e810f82 100644
--- a/xen/include/xen/rangeset.h
+++ b/xen/include/xen/rangeset.h
@@ -56,11 +56,15 @@ void rangeset_limit(
bool __must_check rangeset_is_empty(
const struct rangeset *r);
-/* Add/claim/remove/query/purge a numeric range. */
+/* Add/claim/find/remove/query/purge a numeric range. */
int __must_check rangeset_add_range(
struct rangeset *r, unsigned long s, unsigned long e);
int __must_check rangeset_claim_range(struct rangeset *r, unsigned long size,
unsigned long *s);
+int __must_check rangeset_find_aligned_range(struct rangeset *r,
+ unsigned long size,
+ unsigned long min,
+ unsigned long *s);
int __must_check rangeset_remove_range(
struct rangeset *r, unsigned long s, unsigned long e);
bool __must_check rangeset_contains_range(
--
2.34.1© 2016 - 2025 Red Hat, Inc.