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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [xen master] xen/arm: do not map PCI ECAM and MMIO space to Domain-0's p2m
commit dc27c174b2fc1ba0697ed96dc96066c272e09c24
Author: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx>
AuthorDate: Thu Dec 9 09:29:18 2021 +0200
Commit: Julien Grall <jgrall@xxxxxxxxxx>
CommitDate: Wed Dec 15 17:39:56 2021 +0000
xen/arm: do not map PCI ECAM and MMIO space to Domain-0's p2m
PCI host bridges are special devices in terms of implementing PCI
passthrough. According to [1] the current implementation depends on
Domain-0 to perform the initialization of the relevant PCI host
bridge hardware and perform PCI device enumeration. In order to
achieve that one of the required changes is to not map all the memory
ranges in map_range_to_domain as we traverse the device tree on startup
and perform some additional checks if the range needs to be mapped to
Domain-0.
The generic PCI host controller device tree binding says [2]:
- ranges: As described in IEEE Std 1275-1994, but must provide
at least a definition of non-prefetchable memory. One
or both of prefetchable Memory and IO Space may also
be provided.
- reg : The Configuration Space base address and size, as accessed
from the parent bus. The base address corresponds to
the first bus in the "bus-range" property. If no
"bus-range" is specified, this will be bus 0 (the default).
From the above none of the memory ranges from the "ranges" property
needs to be mapped to Domain-0 at startup as MMIO mapping is going to
be handled dynamically by vPCI as we assign PCI devices, e.g. each
device assigned to Domain-0/guest will have its MMIOs mapped/unmapped
as needed by Xen.
The "reg" property covers not only ECAM space, but may also have other
then the configuration memory ranges described, for example [3]:
- reg: Should contain rc_dbi, config registers location and length.
- reg-names: Must include the following entries:
"rc_dbi": controller configuration registers;
"config": PCIe configuration space registers.
This patch makes it possible to not map all the ranges from the
"ranges" property and also ECAM from the "reg". All the rest from the
"reg" property still needs to be mapped to Domain-0, so the PCI
host bridge remains functional in Domain-0. This is done by first
skipping the mappings while traversing the device tree as it is done for
usual devices and then by calling a dedicated pci_host_bridge_mappings
function which only maps MMIOs required by the host bridges leaving the
regions, needed for vPCI traps, unmapped.
[1]
https://lists.xenproject.org/archives/html/xen-devel/2020-07/msg00777.html
[2]
https://www.kernel.org/doc/Documentation/devicetree/bindings/pci/host-generic-pci.txt
[3]
https://www.kernel.org/doc/Documentation/devicetree/bindings/pci/hisilicon-pcie.txt
Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx>
Reviewed-by: Julien Grall <jgrall@xxxxxxxxxx>
Reviewed-by: Rahul Singh <rahul.singh@xxxxxxx>
Tested-by: Rahul Singh <rahul.singh@xxxxxxx>
---
xen/arch/arm/domain_build.c | 66 ++++++++++++++++++++++----------------
xen/arch/arm/include/asm/pci.h | 10 ++++++
xen/arch/arm/include/asm/setup.h | 13 ++++++++
xen/arch/arm/pci/ecam.c | 14 ++++++++
xen/arch/arm/pci/pci-host-common.c | 50 +++++++++++++++++++++++++++++
xen/arch/arm/pci/pci-host-zynqmp.c | 1 +
6 files changed, 126 insertions(+), 28 deletions(-)
diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
index 6c5d22d9be..6931c022a2 100644
--- a/xen/arch/arm/domain_build.c
+++ b/xen/arch/arm/domain_build.c
@@ -51,12 +51,6 @@ static int __init parse_dom0_mem(const char *s)
}
custom_param("dom0_mem", parse_dom0_mem);
-struct map_range_data
-{
- struct domain *d;
- p2m_type_t p2mt;
-};
-
/* Override macros from asm/page.h to make them work with mfn_t */
#undef virt_to_mfn
#define virt_to_mfn(va) _mfn(__virt_to_mfn(va))
@@ -1720,10 +1714,10 @@ static int __init map_dt_irq_to_domain(const struct
dt_device_node *dev,
const struct dt_irq *dt_irq,
void *data)
{
- struct domain *d = data;
+ struct map_range_data *mr_data = data;
+ struct domain *d = mr_data->d;
unsigned int irq = dt_irq->irq;
int res;
- bool need_mapping = !dt_device_for_passthrough(dev);
if ( irq < NR_LOCAL_IRQS )
{
@@ -1742,18 +1736,16 @@ static int __init map_dt_irq_to_domain(const struct
dt_device_node *dev,
return res;
}
- res = map_irq_to_domain(d, irq, need_mapping, dt_node_name(dev));
+ res = map_irq_to_domain(d, irq, !mr_data->skip_mapping, dt_node_name(dev));
return 0;
}
-static int __init map_range_to_domain(const struct dt_device_node *dev,
- u64 addr, u64 len,
- void *data)
+int __init map_range_to_domain(const struct dt_device_node *dev,
+ u64 addr, u64 len, void *data)
{
struct map_range_data *mr_data = data;
struct domain *d = mr_data->d;
- bool need_mapping = !dt_device_for_passthrough(dev);
int res;
/*
@@ -1776,7 +1768,7 @@ static int __init map_range_to_domain(const struct
dt_device_node *dev,
}
}
- if ( need_mapping )
+ if ( !mr_data->skip_mapping )
{
res = map_regions_p2mt(d,
gaddr_to_gfn(addr),
@@ -1805,23 +1797,21 @@ static int __init map_range_to_domain(const struct
dt_device_node *dev,
* then we may need to perform additional mappings in order to make
* the child resources available to domain 0.
*/
-static int __init map_device_children(struct domain *d,
- const struct dt_device_node *dev,
- p2m_type_t p2mt)
+static int __init map_device_children(const struct dt_device_node *dev,
+ struct map_range_data *mr_data)
{
- struct map_range_data mr_data = { .d = d, .p2mt = p2mt };
- int ret;
-
if ( dt_device_type_is_equal(dev, "pci") )
{
+ int ret;
+
dt_dprintk("Mapping children of %s to guest\n",
dt_node_full_name(dev));
- ret = dt_for_each_irq_map(dev, &map_dt_irq_to_domain, d);
+ ret = dt_for_each_irq_map(dev, &map_dt_irq_to_domain, mr_data);
if ( ret < 0 )
return ret;
- ret = dt_for_each_range(dev, &map_range_to_domain, &mr_data);
+ ret = dt_for_each_range(dev, &map_range_to_domain, mr_data);
if ( ret < 0 )
return ret;
}
@@ -1901,14 +1891,28 @@ static int __init handle_device(struct domain *d,
struct dt_device_node *dev,
unsigned int i;
int res;
u64 addr, size;
- bool need_mapping = !dt_device_for_passthrough(dev);
+ bool own_device = !dt_device_for_passthrough(dev);
+ /*
+ * We want to avoid mapping the MMIO in dom0 for the following cases:
+ * - The device is owned by dom0 (i.e. it has been flagged for
+ * passthrough).
+ * - PCI host bridges with driver in Xen. They will later be mapped by
+ * pci_host_bridge_mappings().
+ */
+ struct map_range_data mr_data = {
+ .d = d,
+ .p2mt = p2mt,
+ .skip_mapping = !own_device ||
+ (is_pci_passthrough_enabled() &&
+ (device_get_class(dev) == DEVICE_PCI_HOSTBRIDGE))
+ };
naddr = dt_number_of_address(dev);
dt_dprintk("%s passthrough = %d naddr = %u\n",
- dt_node_full_name(dev), need_mapping, naddr);
+ dt_node_full_name(dev), own_device, naddr);
- if ( need_mapping )
+ if ( own_device )
{
dt_dprintk("Check if %s is behind the IOMMU and add it\n",
dt_node_full_name(dev));
@@ -1934,14 +1938,13 @@ static int __init handle_device(struct domain *d,
struct dt_device_node *dev,
}
}
- res = handle_device_interrupts(d, dev, need_mapping);
+ res = handle_device_interrupts(d, dev, own_device);
if ( res < 0 )
return res;
/* Give permission and map MMIOs */
for ( i = 0; i < naddr; i++ )
{
- struct map_range_data mr_data = { .d = d, .p2mt = p2mt };
res = dt_device_get_address(dev, i, &addr, &size);
if ( res )
{
@@ -1955,7 +1958,7 @@ static int __init handle_device(struct domain *d, struct
dt_device_node *dev,
return res;
}
- res = map_device_children(d, dev, p2mt);
+ res = map_device_children(dev, &mr_data);
if ( res )
return res;
@@ -3114,7 +3117,14 @@ static int __init construct_dom0(struct domain *d)
return rc;
if ( acpi_disabled )
+ {
rc = prepare_dtb_hwdom(d, &kinfo);
+ if ( rc < 0 )
+ return rc;
+#ifdef CONFIG_HAS_PCI
+ rc = pci_host_bridge_mappings(d);
+#endif
+ }
else
rc = prepare_acpi(d, &kinfo);
diff --git a/xen/arch/arm/include/asm/pci.h b/xen/arch/arm/include/asm/pci.h
index 94f003a07c..7c7449d64f 100644
--- a/xen/arch/arm/include/asm/pci.h
+++ b/xen/arch/arm/include/asm/pci.h
@@ -17,6 +17,8 @@
#ifdef CONFIG_HAS_PCI
+#include <asm/p2m.h>
+
#define pci_to_dev(pcidev) (&(pcidev)->arch.dev)
extern bool pci_passthrough_enabled;
@@ -73,6 +75,9 @@ struct pci_ops {
uint32_t reg, uint32_t len, uint32_t *value);
int (*write)(struct pci_host_bridge *bridge, pci_sbdf_t sbdf,
uint32_t reg, uint32_t len, uint32_t value);
+ bool (*need_p2m_hwdom_mapping)(struct domain *d,
+ struct pci_host_bridge *bridge,
+ uint64_t addr);
};
/*
@@ -97,6 +102,9 @@ int pci_generic_config_write(struct pci_host_bridge *bridge,
pci_sbdf_t sbdf,
uint32_t reg, uint32_t len, uint32_t value);
void __iomem *pci_ecam_map_bus(struct pci_host_bridge *bridge,
pci_sbdf_t sbdf, uint32_t where);
+bool pci_ecam_need_p2m_hwdom_mapping(struct domain *d,
+ struct pci_host_bridge *bridge,
+ uint64_t addr);
struct pci_host_bridge *pci_find_host_bridge(uint16_t segment, uint8_t bus);
struct dt_device_node *pci_find_host_bridge_node(struct device *dev);
int pci_get_host_bridge_segment(const struct dt_device_node *node,
@@ -115,6 +123,8 @@ int pci_host_iterate_bridges_and_count(struct domain *d,
int (*cb)(struct domain *d,
struct pci_host_bridge
*bridge));
+int pci_host_bridge_mappings(struct domain *d);
+
#else /*!CONFIG_HAS_PCI*/
struct arch_pci_dev { };
diff --git a/xen/arch/arm/include/asm/setup.h b/xen/arch/arm/include/asm/setup.h
index 95da0b7ab9..88d9673db8 100644
--- a/xen/arch/arm/include/asm/setup.h
+++ b/xen/arch/arm/include/asm/setup.h
@@ -2,6 +2,8 @@
#define __ARM_SETUP_H_
#include <public/version.h>
+#include <asm/p2m.h>
+#include <xen/device_tree.h>
#define MIN_FDT_ALIGN 8
#define MAX_FDT_SIZE SZ_2M
@@ -77,6 +79,14 @@ struct bootinfo {
#endif
};
+struct map_range_data
+{
+ struct domain *d;
+ p2m_type_t p2mt;
+ /* Set if mapping of the memory ranges must be skipped. */
+ bool skip_mapping;
+};
+
extern struct bootinfo bootinfo;
extern domid_t max_init_domid;
@@ -124,6 +134,9 @@ void device_tree_get_reg(const __be32 **cell, u32
address_cells,
u32 device_tree_get_u32(const void *fdt, int node,
const char *prop_name, u32 dflt);
+int map_range_to_domain(const struct dt_device_node *dev,
+ u64 addr, u64 len, void *data);
+
#endif
/*
* Local variables:
diff --git a/xen/arch/arm/pci/ecam.c b/xen/arch/arm/pci/ecam.c
index 2855dea213..6aeea12a68 100644
--- a/xen/arch/arm/pci/ecam.c
+++ b/xen/arch/arm/pci/ecam.c
@@ -40,6 +40,19 @@ void __iomem *pci_ecam_map_bus(struct pci_host_bridge
*bridge,
return base + (PCI_DEVFN2(sbdf.bdf) << devfn_shift) + where;
}
+bool __init pci_ecam_need_p2m_hwdom_mapping(struct domain *d,
+ struct pci_host_bridge *bridge,
+ uint64_t addr)
+{
+ struct pci_config_window *cfg = bridge->cfg;
+
+ /*
+ * We do not want ECAM address space to be mapped in Domain-0's p2m,
+ * so we can trap access to it.
+ */
+ return cfg->phys_addr != addr;
+}
+
/* ECAM ops */
const struct pci_ecam_ops pci_generic_ecam_ops = {
.bus_shift = 20,
@@ -47,6 +60,7 @@ const struct pci_ecam_ops pci_generic_ecam_ops = {
.map_bus = pci_ecam_map_bus,
.read = pci_generic_config_read,
.write = pci_generic_config_write,
+ .need_p2m_hwdom_mapping = pci_ecam_need_p2m_hwdom_mapping,
}
};
diff --git a/xen/arch/arm/pci/pci-host-common.c
b/xen/arch/arm/pci/pci-host-common.c
index 84aab371cd..fd8c0f837a 100644
--- a/xen/arch/arm/pci/pci-host-common.c
+++ b/xen/arch/arm/pci/pci-host-common.c
@@ -22,6 +22,8 @@
#include <xen/sched.h>
#include <xen/vmap.h>
+#include <asm/setup.h>
+
/*
* List for all the pci host bridges.
*/
@@ -313,6 +315,54 @@ int pci_host_iterate_bridges_and_count(struct domain *d,
return count;
}
+/*
+ * For each PCI host bridge we need to only map those ranges
+ * which are used by Domain-0 to properly initialize the bridge,
+ * e.g. we do not want to map ECAM configuration space which lives in
+ * "reg" device tree property, but we want to map other regions of
+ * the host bridge. The PCI aperture defined by the "ranges" device
+ * tree property should also be skipped.
+ */
+int __init pci_host_bridge_mappings(struct domain *d)
+{
+ struct pci_host_bridge *bridge;
+ struct map_range_data mr_data = {
+ .d = d,
+ .p2mt = p2m_mmio_direct_dev,
+ .skip_mapping = false
+ };
+
+ list_for_each_entry( bridge, &pci_host_bridges, node )
+ {
+ const struct dt_device_node *dev = bridge->dt_node;
+ unsigned int i;
+
+ for ( i = 0; i < dt_number_of_address(dev); i++ )
+ {
+ uint64_t addr, size;
+ int err;
+
+ err = dt_device_get_address(dev, i, &addr, &size);
+ if ( err )
+ {
+ printk(XENLOG_ERR
+ "Unable to retrieve address range index=%u for %s\n",
+ i, dt_node_full_name(dev));
+ return err;
+ }
+
+ if ( bridge->ops->need_p2m_hwdom_mapping(d, bridge, addr) )
+ {
+ err = map_range_to_domain(dev, addr, size, &mr_data);
+ if ( err )
+ return err;
+ }
+ }
+ }
+
+ return 0;
+}
+
/*
* Local variables:
* mode: C
diff --git a/xen/arch/arm/pci/pci-host-zynqmp.c
b/xen/arch/arm/pci/pci-host-zynqmp.c
index 516982bca8..101edb8593 100644
--- a/xen/arch/arm/pci/pci-host-zynqmp.c
+++ b/xen/arch/arm/pci/pci-host-zynqmp.c
@@ -34,6 +34,7 @@ const struct pci_ecam_ops nwl_pcie_ops = {
.map_bus = pci_ecam_map_bus,
.read = pci_generic_config_read,
.write = pci_generic_config_write,
+ .need_p2m_hwdom_mapping = pci_ecam_need_p2m_hwdom_mapping,
}
};
--
generated by git-patchbot for /home/xen/git/xen.git#master
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