[PATCH v3 23/29] iommu/arm-smmu-v3-kvm: Support io-pgtable

[Mostafa Saleh]

Implement the hypervisor version of io-pgtable allocation functions,
mirroring drivers/iommu/io-pgtable-arm.c. Page allocation uses the
IOMMU pool filled by the host.

Signed-off-by: Jean-Philippe Brucker <jean-philippe at linaro.org>
Signed-off-by: Mostafa Saleh <smostafa at google.com>
---
 arch/arm64/kvm/hyp/nvhe/Makefile              |   4 +-
 .../arm/arm-smmu-v3/pkvm/io-pgtable-arm.c     | 115 ++++++++++++++++++
 drivers/iommu/io-pgtable-arm.h                |  15 ++-
 3 files changed, 131 insertions(+), 3 deletions(-)
 create mode 100644 drivers/iommu/arm/arm-smmu-v3/pkvm/io-pgtable-arm.c

diff --git a/arch/arm64/kvm/hyp/nvhe/Makefile b/arch/arm64/kvm/hyp/nvhe/Makefile
index c71c96262378..d641a9987152 100644
--- a/arch/arm64/kvm/hyp/nvhe/Makefile
+++ b/arch/arm64/kvm/hyp/nvhe/Makefile
@@ -34,7 +34,9 @@ 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-hyp.o
+	$(HYP_SMMU_V3_DRV_PATH)/arm-smmu-v3-common-hyp.o \
+	$(HYP_SMMU_V3_DRV_PATH)/pkvm/io-pgtable-arm.o \
+	$(HYP_SMMU_V3_DRV_PATH)/../../io-pgtable-arm-common.o
 
 ##
 ## Build rules for compiling nVHE hyp code
diff --git a/drivers/iommu/arm/arm-smmu-v3/pkvm/io-pgtable-arm.c b/drivers/iommu/arm/arm-smmu-v3/pkvm/io-pgtable-arm.c
new file mode 100644
index 000000000000..ce17f21238c8
--- /dev/null
+++ b/drivers/iommu/arm/arm-smmu-v3/pkvm/io-pgtable-arm.c
@@ -0,0 +1,115 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2022 Arm Ltd.
+ */
+#include <nvhe/iommu.h>
+
+#include "../../../io-pgtable-arm.h"
+
+void arm_lpae_split_blk(void)
+{
+	WARN_ON(1);
+}
+
+void *__arm_lpae_alloc_pages(size_t size, gfp_t gfp,
+			     struct io_pgtable_cfg *cfg, void *cookie)
+{
+	void *addr;
+
+	if (!PAGE_ALIGNED(size))
+		return NULL;
+
+	addr = kvm_iommu_donate_pages(get_order(size));
+
+	if (addr && !cfg->coherent_walk)
+		kvm_flush_dcache_to_poc(addr, size);
+
+	return addr;
+}
+
+void __arm_lpae_free_pages(void *addr, size_t size, struct io_pgtable_cfg *cfg,
+			   void *cookie)
+{
+	if (!cfg->coherent_walk)
+		kvm_flush_dcache_to_poc(addr, size);
+
+	kvm_iommu_reclaim_pages(addr);
+}
+
+void __arm_lpae_sync_pte(arm_lpae_iopte *ptep, int num_entries,
+			 struct io_pgtable_cfg *cfg)
+{
+	if (!cfg->coherent_walk)
+		kvm_flush_dcache_to_poc(ptep, sizeof(*ptep) * num_entries);
+}
+
+static int kvm_arm_io_pgtable_init(struct io_pgtable_cfg *cfg,
+				   enum io_pgtable_fmt fmt,
+				   struct arm_lpae_io_pgtable *data,
+				   void *cookie)
+{
+	int ret = -EINVAL;
+
+	if (fmt == ARM_64_LPAE_S2)
+		ret = arm_lpae_init_pgtable_s2(cfg, data, cookie);
+	else if (fmt == ARM_64_LPAE_S1)
+		ret = arm_lpae_init_pgtable_s1(cfg, data, cookie);
+
+	if (ret)
+		return ret;
+
+	data->iop.cfg = *cfg;
+	data->iop.fmt	= fmt;
+	return 0;
+}
+
+struct io_pgtable *kvm_arm_io_pgtable_alloc(struct io_pgtable_cfg *cfg,
+					    void *cookie,
+					    enum io_pgtable_fmt fmt,
+					    int *out_ret)
+{
+	size_t pgd_size;
+	struct arm_lpae_io_pgtable *data;
+	int ret;
+
+	data = kvm_iommu_donate_pages(get_order(sizeof(*data)));
+	if (!data) {
+		*out_ret = -ENOMEM;
+		return NULL;
+	}
+
+	data->iop.ops = (struct io_pgtable_ops) {
+		.map_pages	= arm_lpae_map_pages,
+		.unmap_pages	= arm_lpae_unmap_pages,
+	};
+
+	ret = kvm_arm_io_pgtable_init(cfg, fmt, data, cookie);
+	if (ret) {
+		*out_ret = ret;
+		goto out_free;
+	}
+	pgd_size = PAGE_ALIGN(ARM_LPAE_PGD_SIZE(data));
+	data->pgd = __arm_lpae_alloc_pages(pgd_size, 0, &data->iop.cfg, cookie);
+	if (!data->pgd) {
+		ret = -ENOMEM;
+		goto out_free;
+	}
+
+	if (fmt == ARM_64_LPAE_S2)
+		data->iop.cfg.arm_lpae_s2_cfg.vttbr = __arm_lpae_virt_to_phys(data->pgd);
+	else if (fmt == ARM_64_LPAE_S1)
+		data->iop.cfg.arm_lpae_s1_cfg.ttbr = __arm_lpae_virt_to_phys(data->pgd);
+
+	if (!data->iop.cfg.coherent_walk)
+		kvm_flush_dcache_to_poc(data->pgd, pgd_size);
+
+	/* Ensure the empty pgd is visible before any actual TTBR write */
+	wmb();
+
+	*out_ret = 0;
+	return &data->iop;
+out_free:
+	kvm_iommu_reclaim_pages(data);
+	*out_ret = ret;
+	return NULL;
+}
diff --git a/drivers/iommu/io-pgtable-arm.h b/drivers/iommu/io-pgtable-arm.h
index 2807cf563f11..c1450eca934f 100644
--- a/drivers/iommu/io-pgtable-arm.h
+++ b/drivers/iommu/io-pgtable-arm.h
@@ -188,8 +188,19 @@ static inline bool iopte_table(arm_lpae_iopte pte, int lvl)
 	return iopte_type(pte) == ARM_LPAE_PTE_TYPE_TABLE;
 }
 
-#define __arm_lpae_virt_to_phys        __pa
-#define __arm_lpae_phys_to_virt        __va
+#ifdef __KVM_NVHE_HYPERVISOR__
+#include <nvhe/memory.h>
+#define __arm_lpae_virt_to_phys	hyp_virt_to_phys
+#define __arm_lpae_phys_to_virt	hyp_phys_to_virt
+
+struct io_pgtable *kvm_arm_io_pgtable_alloc(struct io_pgtable_cfg *cfg,
+					    void *cookie,
+					    enum io_pgtable_fmt fmt,
+					    int *out_ret);
+#else
+#define __arm_lpae_virt_to_phys	__pa
+#define __arm_lpae_phys_to_virt	__va
+#endif
 
 static inline phys_addr_t iopte_to_paddr(arm_lpae_iopte pte,
 					 struct arm_lpae_io_pgtable *data)
-- 
2.50.1.552.g942d659e1b-goog