[PATCH v8 21/25] iommu/io-pgtable-arm: Support io-pgtable-arm in the hypervisor
From: Mostafa Saleh <smostafa@google.com>
Date: 2026-09-22 13:13:31
Also in:
kvmarm, linux-iommu, lkml
Subsystem:
arm smmu drivers, arm64 port (aarch64 architecture), iommu subsystem, kernel virtual machine for arm64 (kvm/arm64), the rest · Maintainers:
Will Deacon, Catalin Marinas, Joerg Roedel, Marc Zyngier, Oliver Upton, Linus Torvalds
To be able to populate the shadow stage-2 in the hypervisor, compile io-pgtable-arm object for the hypervisor. That requires the hypervisor to provide the iommu-pages allocator, redefine the address conversion helpers, and stub out the DMA API. Signed-off-by: Mostafa Saleh <smostafa@google.com> --- arch/arm64/kvm/hyp/nvhe/Makefile | 3 +- .../arm/arm-smmu-v3/pkvm/io-pgtable-arm-hyp.h | 86 +++++++++++++++++++ drivers/iommu/io-pgtable-arm.c | 14 +-- drivers/iommu/io-pgtable-arm.h | 9 ++ 4 files changed, 104 insertions(+), 8 deletions(-) create mode 100644 drivers/iommu/arm/arm-smmu-v3/pkvm/io-pgtable-arm-hyp.h
diff --git a/arch/arm64/kvm/hyp/nvhe/Makefile b/arch/arm64/kvm/hyp/nvhe/Makefile
index aa76c0f3f147..64bfd9992d9e 100644
--- a/arch/arm64/kvm/hyp/nvhe/Makefile
+++ b/arch/arm64/kvm/hyp/nvhe/Makefile@@ -36,7 +36,8 @@ hyp-obj-y += $(lib-objs) HYP_SMMU_V3_DRV_PATH = ../../../../../drivers/iommu/arm/arm-smmu-v3 hyp-obj-$(CONFIG_ARM_SMMU_V3_PKVM) += $(HYP_SMMU_V3_DRV_PATH)/pkvm/arm-smmu-v3.o \ - $(HYP_SMMU_V3_DRV_PATH)/arm-smmu-v3-common-lib.o ../../../../../lib/hweight.o + $(HYP_SMMU_V3_DRV_PATH)/arm-smmu-v3-common-lib.o ../../../../../lib/hweight.o \ + $(HYP_SMMU_V3_DRV_PATH)/../../io-pgtable-arm.o # Path to simple_ring_buffer.c CFLAGS_trace.nvhe.o += -I$(srctree)/kernel/trace/
diff --git a/drivers/iommu/arm/arm-smmu-v3/pkvm/io-pgtable-arm-hyp.h b/drivers/iommu/arm/arm-smmu-v3/pkvm/io-pgtable-arm-hyp.h
new file mode 100644
index 000000000000..16313814e5f8
--- /dev/null
+++ b/drivers/iommu/arm/arm-smmu-v3/pkvm/io-pgtable-arm-hyp.h@@ -0,0 +1,86 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +#ifndef IO_PGTABLE_ARM_HYP_H_ +#define IO_PGTABLE_ARM_HYP_H_ + +#include <nvhe/memory.h> +#include <nvhe/iommu.h> + +#undef WARN_ONCE +#define WARN_ONCE(condition, format...) WARN_ON(condition) + +static inline void *iommu_alloc_pages_node_sz(int nid, gfp_t gfp, size_t size) +{ + return pkvm_iommu_alloc_pages(get_order(size)); +} + +static inline void iommu_free_pages(void *virt) +{ + pkvm_iommu_free_pages(virt); +} + +#define arm_lpae_alloc_data(type) pkvm_iommu_alloc_pages(get_order(sizeof(type))) +#define arm_lpae_free_data(p) pkvm_iommu_free_pages(p) + +#undef phys_to_virt +#define phys_to_virt(x) hyp_phys_to_virt(x) + +#undef virt_to_phys +#define virt_to_phys(x) hyp_virt_to_phys(x) + +/* Stubs used by io-pgtable-arm but no relevant for hypervisor object. */ +#undef dma_map_single +#define dma_map_single(d, p, s, dir) (virt_to_phys(p)) + +#undef dma_unmap_single +#define dma_unmap_single(d, a, s, r) \ + do { (void)(d); (void)(a); (void)(s); (void)(r); } while (0) + +#define dma_sync_single_for_device(d, a, s, r) \ + do { (void)(d); (void)(a); (void)(s); (void)(r); } while (0) + +#undef dma_mapping_error +#define dma_mapping_error(...) (0) + +#undef dev_err +#define dev_err(dev, format, ...) + +#undef iommu_dirty_bitmap_record +#define iommu_dirty_bitmap_record(d, i, l) \ + do { (void)(d); (void)(i); (void)(l); } while (0) + +static inline int iommu_pages_start_incoherent(void *virt, struct device *dma_dev) +{ + return 0; +} + +static inline void iommu_pages_free_incoherent(void *virt, + struct device *dma_dev) +{ +} + +static inline void iommu_pages_flush_incoherent(struct device *dma_dev, + void *virt, size_t offset, + size_t len) +{ +} + +static inline struct io_pgtable_ops *kvm_alloc_io_pgtable_ops(enum io_pgtable_fmt fmt, + struct io_pgtable_cfg *cfg, + void *cookie) +{ + struct io_pgtable *iop; + + if (fmt != ARM_64_LPAE_S2) + return NULL; + + iop = io_pgtable_arm_64_lpae_s2_init_fns.alloc(cfg, cookie); + if (!iop) + return NULL; + + iop->fmt = fmt; + iop->cookie = cookie; + iop->cfg = *cfg; + + return &iop->ops; +} +#endif /* IO_PGTABLE_ARM_HYP_H_ */
diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c
index 476c0e25631a..6b2668c2ef44 100644
--- a/drivers/iommu/io-pgtable-arm.c
+++ b/drivers/iommu/io-pgtable-arm.c@@ -20,7 +20,6 @@ #include <asm/barrier.h> #include "io-pgtable-arm.h" -#include "iommu-pages.h" #define ARM_LPAE_MAX_ADDR_BITS 52 #define ARM_LPAE_S2_MAX_CONCAT_PAGES 16
@@ -301,6 +300,7 @@ static void *__arm_lpae_alloc_pages(size_t size, gfp_t gfp, { struct device *dev = cfg->iommu_dev; void *pages; + int nid = dev ? dev_to_node(dev) : NUMA_NO_NODE; /* * For very small starting-level translation tables the HW requires a
@@ -311,7 +311,7 @@ static void *__arm_lpae_alloc_pages(size_t size, gfp_t gfp, if (cfg->alloc) return __arm_lpae_cfg_alloc(size, gfp, cfg, cookie); - pages = iommu_alloc_pages_node_sz(dev_to_node(dev), gfp, size); + pages = iommu_alloc_pages_node_sz(nid, gfp, size); if (!pages) return NULL;
@@ -650,7 +650,7 @@ static void arm_lpae_free_pgtable(struct io_pgtable *iop) struct arm_lpae_io_pgtable *data = io_pgtable_to_data(iop); __arm_lpae_free_pgtable(data, data->start_level, data->pgd); - kfree(data); + arm_lpae_free_data(data); } static size_t __arm_lpae_unmap(struct arm_lpae_io_pgtable *data,
@@ -964,7 +964,7 @@ arm_lpae_alloc_pgtable(struct io_pgtable_cfg *cfg) if (cfg->oas > ARM_LPAE_MAX_ADDR_BITS) return NULL; - data = kmalloc_obj(*data); + data = arm_lpae_alloc_data(*data); if (!data) return NULL;
@@ -1091,7 +1091,7 @@ arm_64_lpae_alloc_pgtable_s1(struct io_pgtable_cfg *cfg, void *cookie) return &data->iop; out_free_data: - kfree(data); + arm_lpae_free_data(data); return NULL; }
@@ -1187,7 +1187,7 @@ arm_64_lpae_alloc_pgtable_s2(struct io_pgtable_cfg *cfg, void *cookie) return &data->iop; out_free_data: - kfree(data); + arm_lpae_free_data(data); return NULL; }
@@ -1266,7 +1266,7 @@ arm_mali_lpae_alloc_pgtable(struct io_pgtable_cfg *cfg, void *cookie) return &data->iop; out_free_data: - kfree(data); + arm_lpae_free_data(data); return NULL; }
diff --git a/drivers/iommu/io-pgtable-arm.h b/drivers/iommu/io-pgtable-arm.h
index ba7cfdf7afa0..ca765aea8745 100644
--- a/drivers/iommu/io-pgtable-arm.h
+++ b/drivers/iommu/io-pgtable-arm.h@@ -27,4 +27,13 @@ #define ARM_LPAE_TCR_PS_48_BIT 0x5ULL #define ARM_LPAE_TCR_PS_52_BIT 0x6ULL +#ifndef __KVM_NVHE_HYPERVISOR__ +#include "iommu-pages.h" +#define arm_lpae_alloc_data(type) kmalloc_obj(type) +#define arm_lpae_free_data(p) kfree(p) + +#else +#include "arm/arm-smmu-v3/pkvm/io-pgtable-arm-hyp.h" +#endif + #endif /* IO_PGTABLE_ARM_H_ */
--
2.55.0.1082.g2b9226bbc0-goog