[PATCH v6 01/20] s390: Expose protected virtualization through cc_platform_has()
From: "Aneesh Kumar K.V (Arm)" <aneesh.kumar@kernel.org>
Date: 2026-06-04 08:40:29
Also in:
linux-arm-kernel, linux-coco, linux-iommu, linux-s390, lkml
Subsystem:
s390 architecture, the rest · Maintainers:
Heiko Carstens, Vasily Gorbik, Alexander Gordeev, Linus Torvalds
Protected virtualization guests use memory encryption, so advertise that to the rest of the kernel through cc_platform_has(CC_ATTR_MEM_ENCRYPT). s390 already forces DMA mappings to be unencrypted for protected virtualization guests through force_dma_unencrypted(). Add ARCH_HAS_CC_PLATFORM and provide the matching cc_platform_has() implementation Signed-off-by: Aneesh Kumar K.V (Arm) <aneesh.kumar@kernel.org> --- Cc: Halil Pasic <pasic@linux.ibm.com> Cc: Matthew Rosato <mjrosato@linux.ibm.com> Cc: Jaehoon Kim <redacted> --- arch/s390/Kconfig | 1 + arch/s390/mm/init.c | 14 ++++++++++++++ 2 files changed, 15 insertions(+)
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index ecbcbb781e40..9b5e6029e043 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig@@ -87,6 +87,7 @@ config S390 select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2 select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE select ARCH_HAS_CC_CAN_LINK + select ARCH_HAS_CC_PLATFORM select ARCH_HAS_CPU_FINALIZE_INIT select ARCH_HAS_CURRENT_STACK_POINTER select ARCH_HAS_DEBUG_VIRTUAL
diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
index 1f72efc2a579..ad3c6d92b801 100644
--- a/arch/s390/mm/init.c
+++ b/arch/s390/mm/init.c@@ -50,6 +50,7 @@ #include <linux/virtio_anchor.h> #include <linux/virtio_config.h> #include <linux/execmem.h> +#include <linux/cc_platform.h> pgd_t swapper_pg_dir[PTRS_PER_PGD] __section(".bss..swapper_pg_dir"); pgd_t invalid_pg_dir[PTRS_PER_PGD] __section(".bss..invalid_pg_dir");
@@ -140,6 +141,19 @@ bool force_dma_unencrypted(struct device *dev) return is_prot_virt_guest(); } + +bool cc_platform_has(enum cc_attr attr) +{ + switch (attr) { + case CC_ATTR_MEM_ENCRYPT: + return is_prot_virt_guest(); + + default: + return false; + } +} +EXPORT_SYMBOL_GPL(cc_platform_has); + /* protected virtualization */ static void __init pv_init(void) {
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2.43.0