Re: [PATCH v5 08/11] xen/arm: Enable the existing x86 virtual PCI support for ARM.

[Julien Grall <julien@xxxxxxx>]

Hi Rahul,

On 06/10/2021 18:40, Rahul Singh wrote:
> diff --git a/xen/include/asm-arm/domain.h b/xen/include/asm-arm/domain.h
> index c9277b5c6d..91d614b37e 100644
> --- a/xen/include/asm-arm/domain.h
> +++ b/xen/include/asm-arm/domain.h
> @@ -2,6 +2,7 @@
>   #define __ASM_DOMAIN_H__
>   
>   #include <xen/cache.h>
> +#include <xen/nospec.h>
>   #include <xen/timer.h>
>   #include <asm/page.h>
>   #include <asm/p2m.h>
> @@ -262,7 +263,11 @@ 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.
> + */
This is the sort of comment that will easily get rot if we change the 
behavior on x86. But I find a bit odd to justify the implementation 
based on x86. Can we simply avoid to mention x86?
> +#define has_vpci(d) evaluate_nospec((d)->options & XEN_DOMCTL_CDF_vpci)
>   
>   #endif /* __ASM_DOMAIN_H__ */
>   
> diff --git a/xen/include/asm-x86/pci.h b/xen/include/asm-x86/pci.h
> index e076951032..c4a4fdcbc2 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 d46c61fca9..44be337dec 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 × 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/xen/pci.h b/xen/include/xen/pci.h
> index 70ac25345c..43b8a08170 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 MMCFG_BDF(addr)  (((addr) & 0x0ffff000) >> 12)
> +
>   typedef union {
>       uint32_t sbdf;
>       struct {
Cheers,

--
Julien Grall