From fa1f57421e0b1c57843902c89728f823abc32f02 Mon Sep 17 00:00:00 2001 From: Juergen Gross Date: Thu, 2 Jun 2022 22:23:49 +0300 Subject: [PATCH] xen/virtio: Enable restricted memory access using Xen grant mappings In order to support virtio in Xen guests add a config option XEN_VIRTIO enabling the user to specify whether in all Xen guests virtio should be able to access memory via Xen grant mappings only on the host side. Also set PLATFORM_VIRTIO_RESTRICTED_MEM_ACCESS feature from the guest initialization code on Arm and x86 if CONFIG_XEN_VIRTIO is enabled. Signed-off-by: Juergen Gross Signed-off-by: Oleksandr Tyshchenko Reviewed-by: Stefano Stabellini Reviewed-by: Boris Ostrovsky Link: https://lore.kernel.org/r/1654197833-25362-5-git-send-email-olekstysh@gmail.com Signed-off-by: Juergen Gross --- arch/arm/xen/enlighten.c | 2 ++ arch/x86/xen/enlighten_hvm.c | 2 ++ arch/x86/xen/enlighten_pv.c | 2 ++ drivers/xen/Kconfig | 11 +++++++++++ include/xen/xen.h | 8 ++++++++ 5 files changed, 25 insertions(+) diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c index 07eb69f9e7df..1f9c3ba32833 100644 --- a/arch/arm/xen/enlighten.c +++ b/arch/arm/xen/enlighten.c @@ -443,6 +443,8 @@ static int __init xen_guest_init(void) if (!xen_domain()) return 0; + xen_set_restricted_virtio_memory_access(); + if (!acpi_disabled) xen_acpi_guest_init(); else diff --git a/arch/x86/xen/enlighten_hvm.c b/arch/x86/xen/enlighten_hvm.c index 517a9d8d8f94..8b71b1dd7639 100644 --- a/arch/x86/xen/enlighten_hvm.c +++ b/arch/x86/xen/enlighten_hvm.c @@ -195,6 +195,8 @@ static void __init xen_hvm_guest_init(void) if (xen_pv_domain()) return; + xen_set_restricted_virtio_memory_access(); + init_hvm_pv_info(); reserve_shared_info(); diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c index f33a4421e7cd..e3297b15701c 100644 --- a/arch/x86/xen/enlighten_pv.c +++ b/arch/x86/xen/enlighten_pv.c @@ -109,6 +109,8 @@ static DEFINE_PER_CPU(struct tls_descs, shadow_tls_desc); static void __init xen_pv_init_platform(void) { + xen_set_restricted_virtio_memory_access(); + populate_extra_pte(fix_to_virt(FIX_PARAVIRT_BOOTMAP)); set_fixmap(FIX_PARAVIRT_BOOTMAP, xen_start_info->shared_info); diff --git a/drivers/xen/Kconfig b/drivers/xen/Kconfig index 313a9127fd5c..a7bd8ce7a1d2 100644 --- a/drivers/xen/Kconfig +++ b/drivers/xen/Kconfig @@ -339,4 +339,15 @@ config XEN_GRANT_DMA_OPS bool select DMA_OPS +config XEN_VIRTIO + bool "Xen virtio support" + depends on VIRTIO + select XEN_GRANT_DMA_OPS + help + Enable virtio support for running as Xen guest. Depending on the + guest type this will require special support on the backend side + (qemu or kernel, depending on the virtio device types used). + + If in doubt, say n. + endmenu diff --git a/include/xen/xen.h b/include/xen/xen.h index a99bab817523..0780a81e140d 100644 --- a/include/xen/xen.h +++ b/include/xen/xen.h @@ -52,6 +52,14 @@ bool xen_biovec_phys_mergeable(const struct bio_vec *vec1, extern u64 xen_saved_max_mem_size; #endif +#include + +static inline void xen_set_restricted_virtio_memory_access(void) +{ + if (IS_ENABLED(CONFIG_XEN_VIRTIO) && xen_domain()) + platform_set(PLATFORM_VIRTIO_RESTRICTED_MEM_ACCESS); +} + #ifdef CONFIG_XEN_UNPOPULATED_ALLOC int xen_alloc_unpopulated_pages(unsigned int nr_pages, struct page **pages); void xen_free_unpopulated_pages(unsigned int nr_pages, struct page **pages); -- 2.11.0