On 27.04.22 18:30, Michael Kelley (LINUX) wrote:
From: Juergen Gross <jgross@xxxxxxxx> Sent: Wednesday, April 27, 2022 8:34 AMInstead of using arch_has_restricted_virtio_memory_access() together with CONFIG_ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS, replace those with platform_has() and a new platform feature PLATFORM_VIRTIO_RESTRICTED_MEM_ACCESS. Signed-off-by: Juergen Gross <jgross@xxxxxxxx> --- V2: - move setting of PLATFORM_VIRTIO_RESTRICTED_MEM_ACCESS in SEV case to sev_setup_arch(). --- arch/s390/Kconfig | 1 - arch/s390/mm/init.c | 13 +++---------- arch/x86/Kconfig | 1 - arch/x86/kernel/cpu/mshyperv.c | 5 ++++- arch/x86/mm/mem_encrypt.c | 6 ------ arch/x86/mm/mem_encrypt_amd.c | 4 ++++ drivers/virtio/Kconfig | 6 ------ drivers/virtio/virtio.c | 5 ++--- include/linux/platform-feature.h | 3 ++- include/linux/virtio_config.h | 9 --------- 10 files changed, 15 insertions(+), 38 deletions(-) diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index e084c72104f8..f97a22ae69a8 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -772,7 +772,6 @@ menu "Virtualization" config PROTECTED_VIRTUALIZATION_GUEST def_bool n prompt "Protected virtualization guest support" - select ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS help Select this option, if you want to be able to run this kernel as a protected virtualization KVM guest. diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c index 86ffd0d51fd5..2c3b451813ed 100644 --- a/arch/s390/mm/init.c +++ b/arch/s390/mm/init.c @@ -31,6 +31,7 @@ #include <linux/cma.h> #include <linux/gfp.h> #include <linux/dma-direct.h> +#include <linux/platform-feature.h> #include <asm/processor.h> #include <linux/uaccess.h> #include <asm/pgalloc.h> @@ -168,22 +169,14 @@ bool force_dma_unencrypted(struct device *dev) return is_prot_virt_guest(); } -#ifdef CONFIG_ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS - -int arch_has_restricted_virtio_memory_access(void) -{ - return is_prot_virt_guest(); -} -EXPORT_SYMBOL(arch_has_restricted_virtio_memory_access); - -#endif - /* protected virtualization */ static void pv_init(void) { if (!is_prot_virt_guest()) return; + platform_set(PLATFORM_VIRTIO_RESTRICTED_MEM_ACCESS); + /* make sure bounce buffers are shared */ swiotlb_force = SWIOTLB_FORCE; swiotlb_init(1); diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index b0142e01002e..20ac72546ae4 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1515,7 +1515,6 @@ config X86_CPA_STATISTICS config X86_MEM_ENCRYPT select ARCH_HAS_FORCE_DMA_UNENCRYPTED select DYNAMIC_PHYSICAL_MASK - select ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS def_bool n config AMD_MEM_ENCRYPT diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c index 4b67094215bb..965518b9d14b 100644 --- a/arch/x86/kernel/cpu/mshyperv.c +++ b/arch/x86/kernel/cpu/mshyperv.c @@ -19,6 +19,7 @@ #include <linux/i8253.h> #include <linux/random.h> #include <linux/swiotlb.h> +#include <linux/platform-feature.h> #include <asm/processor.h> #include <asm/hypervisor.h> #include <asm/hyperv-tlfs.h> @@ -347,8 +348,10 @@ static void __init ms_hyperv_init_platform(void) #endif /* Isolation VMs are unenlightened SEV-based VMs, thus this check: */ if (IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT)) { - if (hv_get_isolation_type() != HV_ISOLATION_TYPE_NONE) + if (hv_get_isolation_type() != HV_ISOLATION_TYPE_NONE) { cc_set_vendor(CC_VENDOR_HYPERV); + platform_set(PLATFORM_VIRTIO_RESTRICTED_MEM_ACCESS); + } } }Unless I'm misunderstanding something, the Hyper-V specific change isn't needed. Hyper-V doesn't support virtio in the first place, so it's a bit unexpected be setting a virtio-related flag in Hyper-V code. Also, Hyper-V guests call sev_setup_arch() with CC_ATTR_GUEST_MEM_ENCRYPT set, so this virtio-related flag will get set anyway via that path.
Okay, thanks. Will drop that chunk then. Juergen
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