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[xen staging] xen/arm: Enable the existing x86 virtual PCI support for ARM



commit d59168dc05a5f98b12a7e243268c7d1050c8676c
Author:     Rahul Singh <rahul.singh@xxxxxxx>
AuthorDate: Fri Oct 15 17:51:42 2021 +0100
Commit:     Stefano Stabellini <stefano.stabellini@xxxxxxxxxx>
CommitDate: Fri Oct 15 12:40:21 2021 -0700

    xen/arm: Enable the existing x86 virtual PCI support for ARM
    
    The existing VPCI support available for X86 is adapted for Arm.
    When the device is added to XEN via the hyper call
    â??PHYSDEVOP_pci_device_addâ??, VPCI handler for the config space
    access is added to the Xen to emulate the PCI devices config space.
    
    A MMIO trap handler for the PCI ECAM space is registered in XEN
    so that when guest is trying to access the PCI config space,XEN
    will trap the access and emulate read/write using the VPCI and
    not the real PCI hardware.
    
    For Dom0less systems scan_pci_devices() would be used to discover the
    PCI device in XEN and VPCI handler will be added during XEN boots.
    
    This patch is also doing some small fixes to fix compilation errors on
    arm32 of vpci and prevent 64bit accesses on 32bit:
    - use %zu instead of lu in header.c for print
    - prevent 64bit accesses in vpci_access_allowed
    - ifdef out using CONFIG_64BIT handling of len 8 in
    vpci_ecam_{read/write}
    
    TODO: currently vpci_add_handlers is marked as __hwdom_init, but on ARM
    vpci_add_handlers can be called after boot from
    PHYSDEVOP_pci_device_add. Consider removing __hwdom_init.
    
    Signed-off-by: Rahul Singh <rahul.singh@xxxxxxx>
    Signed-off-by: Bertrand Marquis <bertrand.marquis@xxxxxxx>
    [stefano: add TODO item to commit message]
    Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxx>
    Acked-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
    Reviewed-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>
---
 xen/arch/arm/Makefile         |  1 +
 xen/arch/arm/domain.c         |  4 +++
 xen/arch/arm/vpci.c           | 77 +++++++++++++++++++++++++++++++++++++++++++
 xen/arch/arm/vpci.h           | 36 ++++++++++++++++++++
 xen/drivers/passthrough/pci.c | 13 ++++++++
 xen/drivers/vpci/header.c     |  2 +-
 xen/drivers/vpci/vpci.c       | 10 ++++++
 xen/include/asm-arm/domain.h  |  1 +
 xen/include/public/arch-arm.h |  7 ++++
 xen/include/xen/pci.h         |  2 ++
 10 files changed, 152 insertions(+), 1 deletion(-)

diff --git a/xen/arch/arm/Makefile b/xen/arch/arm/Makefile
index 64518848b2..07f634508e 100644
--- a/xen/arch/arm/Makefile
+++ b/xen/arch/arm/Makefile
@@ -7,6 +7,7 @@ ifneq ($(CONFIG_NO_PLAT),y)
 obj-y += platforms/
 endif
 obj-$(CONFIG_TEE) += tee/
+obj-$(CONFIG_HAS_VPCI) += vpci.o
 
 obj-$(CONFIG_HAS_ALTERNATIVE) += alternative.o
 obj-y += bootfdt.init.o
diff --git a/xen/arch/arm/domain.c b/xen/arch/arm/domain.c
index eef0661beb..96e1b23550 100644
--- a/xen/arch/arm/domain.c
+++ b/xen/arch/arm/domain.c
@@ -39,6 +39,7 @@
 #include <asm/vgic.h>
 #include <asm/vtimer.h>
 
+#include "vpci.h"
 #include "vuart.h"
 
 DEFINE_PER_CPU(struct vcpu *, curr_vcpu);
@@ -773,6 +774,9 @@ int arch_domain_create(struct domain *d,
     if ( is_hardware_domain(d) && (rc = domain_vuart_init(d)) )
         goto fail;
 
+    if ( (rc = domain_vpci_init(d)) != 0 )
+        goto fail;
+
     return 0;
 
 fail:
diff --git a/xen/arch/arm/vpci.c b/xen/arch/arm/vpci.c
new file mode 100644
index 0000000000..8f40a0dec6
--- /dev/null
+++ b/xen/arch/arm/vpci.c
@@ -0,0 +1,77 @@
+/*
+ * xen/arch/arm/vpci.c
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+#include <xen/sched.h>
+#include <xen/vpci.h>
+
+#include <asm/mmio.h>
+
+static int vpci_mmio_read(struct vcpu *v, mmio_info_t *info,
+                          register_t *r, void *p)
+{
+    pci_sbdf_t sbdf;
+    /* data is needed to prevent a pointer cast on 32bit */
+    unsigned long data;
+
+    /* We ignore segment part and always handle segment 0 */
+    sbdf.sbdf = VPCI_ECAM_BDF(info->gpa);
+
+    if ( vpci_ecam_read(sbdf, ECAM_REG_OFFSET(info->gpa),
+                        1U << info->dabt.size, &data) )
+    {
+        *r = data;
+        return 1;
+    }
+
+    *r = ~0ul;
+
+    return 0;
+}
+
+static int vpci_mmio_write(struct vcpu *v, mmio_info_t *info,
+                           register_t r, void *p)
+{
+    pci_sbdf_t sbdf;
+
+    /* We ignore segment part and always handle segment 0 */
+    sbdf.sbdf = VPCI_ECAM_BDF(info->gpa);
+
+    return vpci_ecam_write(sbdf, ECAM_REG_OFFSET(info->gpa),
+                           1U << info->dabt.size, r);
+}
+
+static const struct mmio_handler_ops vpci_mmio_handler = {
+    .read  = vpci_mmio_read,
+    .write = vpci_mmio_write,
+};
+
+int domain_vpci_init(struct domain *d)
+{
+    if ( !has_vpci(d) )
+        return 0;
+
+    register_mmio_handler(d, &vpci_mmio_handler,
+                          GUEST_VPCI_ECAM_BASE, GUEST_VPCI_ECAM_SIZE, NULL);
+
+    return 0;
+}
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
+
diff --git a/xen/arch/arm/vpci.h b/xen/arch/arm/vpci.h
new file mode 100644
index 0000000000..d8a7b0e3e8
--- /dev/null
+++ b/xen/arch/arm/vpci.h
@@ -0,0 +1,36 @@
+/*
+ * xen/arch/arm/vpci.h
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef __ARCH_ARM_VPCI_H__
+#define __ARCH_ARM_VPCI_H__
+
+#ifdef CONFIG_HAS_VPCI
+int domain_vpci_init(struct domain *d);
+#else
+static inline int domain_vpci_init(struct domain *d)
+{
+    return 0;
+}
+#endif
+
+#endif /* __ARCH_ARM_VPCI_H__ */
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
diff --git a/xen/drivers/passthrough/pci.c b/xen/drivers/passthrough/pci.c
index 3aa8c3175f..35e0190796 100644
--- a/xen/drivers/passthrough/pci.c
+++ b/xen/drivers/passthrough/pci.c
@@ -756,6 +756,19 @@ int pci_add_device(u16 seg, u8 bus, u8 devfn,
     if ( !pdev->domain )
     {
         pdev->domain = hardware_domain;
+#ifdef CONFIG_ARM
+        /*
+         * On ARM PCI devices discovery will be done by Dom0. Add vpci handler
+         * when Dom0 inform XEN to add the PCI devices in XEN.
+         */
+        ret = vpci_add_handlers(pdev);
+        if ( ret )
+        {
+            printk(XENLOG_ERR "Setup of vPCI failed: %d\n", ret);
+            pdev->domain = NULL;
+            goto out;
+        }
+#endif
         ret = iommu_add_device(pdev);
         if ( ret )
         {
diff --git a/xen/drivers/vpci/header.c b/xen/drivers/vpci/header.c
index f8cd55e7c0..40ff79c33f 100644
--- a/xen/drivers/vpci/header.c
+++ b/xen/drivers/vpci/header.c
@@ -373,7 +373,7 @@ static void bar_write(const struct pci_dev *pdev, unsigned 
int reg,
         /* If the value written is the current one avoid printing a warning. */
         if ( val != (uint32_t)(bar->addr >> (hi ? 32 : 0)) )
             gprintk(XENLOG_WARNING,
-                    "%pp: ignored BAR %lu write with memory decoding 
enabled\n",
+                    "%pp: ignored BAR %zu write with memory decoding 
enabled\n",
                     &pdev->sbdf, bar - pdev->vpci->header.bars + hi);
         return;
     }
diff --git a/xen/drivers/vpci/vpci.c b/xen/drivers/vpci/vpci.c
index ef690f15a9..decf7d87a1 100644
--- a/xen/drivers/vpci/vpci.c
+++ b/xen/drivers/vpci/vpci.c
@@ -485,6 +485,12 @@ bool vpci_access_allowed(unsigned int reg, unsigned int 
len)
     if ( len != 1 && len != 2 && len != 4 && len != 8 )
         return false;
 
+#ifndef CONFIG_64BIT
+    /* Prevent 64bit accesses on 32bit */
+    if ( len == 8 )
+        return false;
+#endif
+
     /* Check that access is size aligned. */
     if ( (reg & (len - 1)) )
         return false;
@@ -500,8 +506,10 @@ bool vpci_ecam_write(pci_sbdf_t sbdf, unsigned int reg, 
unsigned int len,
         return false;
 
     vpci_write(sbdf, reg, min(4u, len), data);
+#ifdef CONFIG_64BIT
     if ( len == 8 )
         vpci_write(sbdf, reg + 4, 4, data >> 32);
+#endif
 
     return true;
 }
@@ -526,8 +534,10 @@ bool vpci_ecam_read(pci_sbdf_t sbdf, unsigned int reg, 
unsigned int len,
      *  4byte accesses.
      */
     *data = vpci_read(sbdf, reg, min(4u, len));
+#ifdef CONFIG_64BIT
     if ( len == 8 )
         *data |= (uint64_t)vpci_read(sbdf, reg + 4, 4) << 32;
+#endif
 
     return true;
 }
diff --git a/xen/include/asm-arm/domain.h b/xen/include/asm-arm/domain.h
index 14e575288f..9b3647587a 100644
--- a/xen/include/asm-arm/domain.h
+++ b/xen/include/asm-arm/domain.h
@@ -263,6 +263,7 @@ static inline void arch_vcpu_block(struct vcpu *v) {}
 
 #define arch_vm_assist_valid_mask(d) (1UL << VMASST_TYPE_runstate_update_flag)
 
+/* vPCI is not available on Arm */
 #define has_vpci(d)    ({ (void)(d); false; })
 
 #endif /* __ASM_DOMAIN_H__ */
diff --git a/xen/include/public/arch-arm.h b/xen/include/public/arch-arm.h
index 96ead3de07..b4c615bcdf 100644
--- a/xen/include/public/arch-arm.h
+++ b/xen/include/public/arch-arm.h
@@ -418,6 +418,13 @@ typedef uint64_t xen_callback_t;
 #define GUEST_GICV3_GICR0_BASE     xen_mk_ullong(0x03020000) /* vCPU0..127 */
 #define GUEST_GICV3_GICR0_SIZE     xen_mk_ullong(0x01000000)
 
+/*
+ * 256 MB is reserved for VPCI configuration space based on calculation
+ * 256 buses x 32 devices x 8 functions x 4 KB = 256 MB
+ */
+#define GUEST_VPCI_ECAM_BASE    xen_mk_ullong(0x10000000)
+#define GUEST_VPCI_ECAM_SIZE    xen_mk_ullong(0x10000000)
+
 /* ACPI tables physical address */
 #define GUEST_ACPI_BASE xen_mk_ullong(0x20000000)
 #define GUEST_ACPI_SIZE xen_mk_ullong(0x02000000)
diff --git a/xen/include/xen/pci.h b/xen/include/xen/pci.h
index 70ac25345c..b6d7e454f8 100644
--- a/xen/include/xen/pci.h
+++ b/xen/include/xen/pci.h
@@ -40,6 +40,8 @@
 #define PCI_SBDF3(s,b,df) \
     ((pci_sbdf_t){ .sbdf = (((s) & 0xffff) << 16) | PCI_BDF2(b, df) })
 
+#define ECAM_REG_OFFSET(addr)  ((addr) & 0x00000fff)
+
 typedef union {
     uint32_t sbdf;
     struct {
--
generated by git-patchbot for /home/xen/git/xen.git#staging



 


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