On Wed, 22 Sep 2021, Rahul Singh wrote: > The existing VPCI support available for X86 is adapted for Arm. > When the device is added to XEN via the hyper call > “PHYSDEVOP_pci_device_add”, 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. > > Signed-off-by: Rahul Singh > --- > Change in v2: > - Add new XEN_DOMCTL_CDF_vpci flag > - modify has_vpci() to include XEN_DOMCTL_CDF_vpci > - enable vpci support when pci-passthough option is enabled. > --- > xen/arch/arm/Makefile | 1 + > xen/arch/arm/domain.c | 6 +- > xen/arch/arm/domain_build.c | 3 + > xen/arch/arm/vpci.c | 102 ++++++++++++++++++++++++++++++++++ > xen/arch/arm/vpci.h | 36 ++++++++++++ > xen/common/domain.c | 2 +- > xen/drivers/passthrough/pci.c | 12 ++++ > xen/include/asm-arm/domain.h | 8 ++- > xen/include/asm-x86/pci.h | 2 - > xen/include/public/arch-arm.h | 7 +++ > xen/include/public/domctl.h | 4 +- > xen/include/xen/pci.h | 2 + > 12 files changed, 179 insertions(+), 6 deletions(-) > create mode 100644 xen/arch/arm/vpci.c > create mode 100644 xen/arch/arm/vpci.h > > diff --git a/xen/arch/arm/Makefile b/xen/arch/arm/Makefile > index 44d7cc81fa..fb9c976ea2 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 19c756ac3d..f7ed130023 100644 > --- a/xen/arch/arm/domain.c > +++ b/xen/arch/arm/domain.c > @@ -39,6 +39,7 @@ > #include > #include > > +#include "vpci.h" > #include "vuart.h" > > DEFINE_PER_CPU(struct vcpu *, curr_vcpu); > @@ -623,7 +624,7 @@ int arch_sanitise_domain_config(struct xen_domctl_createdomain *config) > unsigned int max_vcpus; > > /* HVM and HAP must be set. IOMMU may or may not be */ > - if ( (config->flags & ~XEN_DOMCTL_CDF_iommu) != > + if ( (config->flags & ~XEN_DOMCTL_CDF_iommu & ~XEN_DOMCTL_CDF_vpci) != > (XEN_DOMCTL_CDF_hvm | XEN_DOMCTL_CDF_hap) ) > { > dprintk(XENLOG_INFO, "Unsupported configuration %#x\n", > @@ -767,6 +768,9 @@ 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/domain_build.c b/xen/arch/arm/domain_build.c > index d233d634c1..5eb83b12a1 100644 > --- a/xen/arch/arm/domain_build.c > +++ b/xen/arch/arm/domain_build.c > @@ -2773,6 +2773,9 @@ void __init create_dom0(void) > if ( iommu_enabled ) > dom0_cfg.flags |= XEN_DOMCTL_CDF_iommu; > > + if ( pci_passthrough_enabled ) we should use the accessor function instead is_pci_passthrough_enabled > + dom0_cfg.flags |= XEN_DOMCTL_CDF_vpci; > + > dom0 = domain_create(0, &dom0_cfg, true); > if ( IS_ERR(dom0) || (alloc_dom0_vcpu0(dom0) == NULL) ) > panic("Error creating domain 0\n"); > diff --git a/xen/arch/arm/vpci.c b/xen/arch/arm/vpci.c > new file mode 100644 > index 0000000000..76c12b9281 > --- /dev/null > +++ b/xen/arch/arm/vpci.c > @@ -0,0 +1,102 @@ > +/* > + * 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 > + > +#include > + > +#define REGISTER_OFFSET(addr) ( (addr) & 0x00000fff) > + > +/* Do some sanity checks. */ > +static bool vpci_mmio_access_allowed(unsigned int reg, unsigned int len) > +{ > + /* Check access size. */ > + if ( len > 8 ) > + return false; > + > + /* Check that access is size aligned. */ > + if ( (reg & (len - 1)) ) > + return false; > + > + return true; > +} > + > +static int vpci_mmio_read(struct vcpu *v, mmio_info_t *info, > + register_t *r, void *p) > +{ > + unsigned int reg; > + pci_sbdf_t sbdf; > + unsigned long data = ~0UL; > + unsigned int size = 1U << info->dabt.size; > + > + sbdf.sbdf = MMCFG_BDF(info->gpa); > + reg = REGISTER_OFFSET(info->gpa); > + > + if ( !vpci_mmio_access_allowed(reg, size) ) > + return 0; > + > + data = vpci_read(sbdf, reg, min(4u, size)); > + if ( size == 8 ) > + data |= (uint64_t)vpci_read(sbdf, reg + 4, 4) << 32; > + > + *r = data; > + > + return 1; > +} > + > +static int vpci_mmio_write(struct vcpu *v, mmio_info_t *info, > + register_t r, void *p) > +{ > + unsigned int reg; > + pci_sbdf_t sbdf; > + unsigned long data = r; > + unsigned int size = 1U << info->dabt.size; > + > + sbdf.sbdf = MMCFG_BDF(info->gpa); > + reg = REGISTER_OFFSET(info->gpa); > + > + if ( !vpci_mmio_access_allowed(reg, size) ) > + return 0; > + > + vpci_write(sbdf, reg, min(4u, size), data); > + if ( size == 8 ) > + vpci_write(sbdf, reg + 4, 4, data >> 32); > + > + return 1; > +} > + > +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/common/domain.c b/xen/common/domain.c > index 6ee5d033b0..40d67ec342 100644 > --- a/xen/common/domain.c > +++ b/xen/common/domain.c > @@ -483,7 +483,7 @@ static int sanitise_domain_config(struct xen_domctl_createdomain *config) > ~(XEN_DOMCTL_CDF_hvm | XEN_DOMCTL_CDF_hap | > XEN_DOMCTL_CDF_s3_integrity | XEN_DOMCTL_CDF_oos_off | > XEN_DOMCTL_CDF_xs_domain | XEN_DOMCTL_CDF_iommu | > - XEN_DOMCTL_CDF_nested_virt) ) > + XEN_DOMCTL_CDF_nested_virt | XEN_DOMCTL_CDF_vpci) ) > { > dprintk(XENLOG_INFO, "Unknown CDF flags %#x\n", config->flags); > return -EINVAL; > diff --git a/xen/drivers/passthrough/pci.c b/xen/drivers/passthrough/pci.c > index d774a6154e..633e89ac13 100644 > --- a/xen/drivers/passthrough/pci.c > +++ b/xen/drivers/passthrough/pci.c > @@ -767,6 +767,18 @@ int pci_add_device(u16 seg, u8 bus, u8 devfn, > else > iommu_enable_device(pdev); > > +#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. > + */ I take this is not needed on x86 because for vpci is only used by Dom0 PVH? It would be good to clarify either way. > + ret = vpci_add_handlers(pdev); > + if ( ret ) { > + printk(XENLOG_ERR "setup of vPCI for failed: %d\n",ret); > + goto out; > + } > +#endif > + > pci_enable_acs(pdev); > > out: > diff --git a/xen/include/asm-arm/domain.h b/xen/include/asm-arm/domain.h > index c9277b5c6d..5fb4e24adf 100644 > --- a/xen/include/asm-arm/domain.h > +++ b/xen/include/asm-arm/domain.h > @@ -2,6 +2,7 @@ > #define __ASM_DOMAIN_H__ > > #include > +#include > #include > #include > #include > @@ -262,7 +263,12 @@ static inline void arch_vcpu_block(struct vcpu *v) {} > > #define arch_vm_assist_valid_mask(d) (1UL << VMASST_TYPE_runstate_update_flag) > > -#define has_vpci(d) ({ (void)(d); false; }) > +/* > + * For X86 VPCI is enabled and tested for PVH DOM0 only but > + * for ARM we enable support VPCI for guest domain also. > + */ > +#define has_vpci(d) ((void)(d), IS_ENABLED(CONFIG_HAS_VPCI) && \ > + evaluate_nospec(d->options & XEN_DOMCTL_CDF_vpci)) With the new options & XEN_DOMCTL_CDF_vpci check in place, do we even need IS_ENABLED(CONFIG_HAS_VPCI) any longer? > #endif /* __ASM_DOMAIN_H__ */ > > diff --git a/xen/include/asm-x86/pci.h b/xen/include/asm-x86/pci.h > index 0e160c6d01..a5590557db 100644 > --- a/xen/include/asm-x86/pci.h > +++ b/xen/include/asm-x86/pci.h > @@ -6,8 +6,6 @@ > #define CF8_ADDR_HI(cf8) ( ((cf8) & 0x0f000000) >> 16) > #define CF8_ENABLED(cf8) (!!((cf8) & 0x80000000)) > > -#define MMCFG_BDF(addr) ( ((addr) & 0x0ffff000) >> 12) > - > #define IS_SNB_GFX(id) (id == 0x01068086 || id == 0x01168086 \ > || id == 0x01268086 || id == 0x01028086 \ > || id == 0x01128086 || id == 0x01228086 \ > diff --git a/xen/include/public/arch-arm.h b/xen/include/public/arch-arm.h > index 6b5a5f818a..727541a321 100644 > --- a/xen/include/public/arch-arm.h > +++ b/xen/include/public/arch-arm.h > @@ -416,6 +416,13 @@ 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 × 32 devices × 8 functions × 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/public/domctl.h b/xen/include/public/domctl.h > index 96696e3842..4245da3f45 100644 > --- a/xen/include/public/domctl.h > +++ b/xen/include/public/domctl.h > @@ -70,9 +70,11 @@ struct xen_domctl_createdomain { > #define XEN_DOMCTL_CDF_iommu (1U<<_XEN_DOMCTL_CDF_iommu) > #define _XEN_DOMCTL_CDF_nested_virt 6 > #define XEN_DOMCTL_CDF_nested_virt (1U << _XEN_DOMCTL_CDF_nested_virt) > +#define _XEN_DOMCTL_CDF_vpci 7 > +#define XEN_DOMCTL_CDF_vpci (1U << _XEN_DOMCTL_CDF_vpci) > > /* Max XEN_DOMCTL_CDF_* constant. Used for ABI checking. */ > -#define XEN_DOMCTL_CDF_MAX XEN_DOMCTL_CDF_nested_virt > +#define XEN_DOMCTL_CDF_MAX XEN_DOMCTL_CDF_vpci > > uint32_t flags; > > diff --git a/xen/include/xen/pci.h b/xen/include/xen/pci.h > index 8e3d4d9454..2b2dfb6f1b 100644 > --- a/xen/include/xen/pci.h > +++ b/xen/include/xen/pci.h > @@ -41,6 +41,8 @@ > #define PCI_SBDF3(s,b,df) \ > ((pci_sbdf_t){ .sbdf = (((s) & 0xffff) << 16) | PCI_BDF2(b, df) }) > > +#define MMCFG_BDF(addr) ( ((addr) & 0x0ffff000) >> 12) > + > typedef union { > uint32_t sbdf; > struct { > -- > 2.17.1 >