| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <20251221160920.297689-3-aneesh.kumar@kernel.org>
Date: Sun, 21 Dec 2025 21:39:18 +0530
From: "Aneesh Kumar K.V (Arm)" <aneesh.kumar@...nel.org>
To: linux-kernel@...r.kernel.org,
iommu@...ts.linux.dev,
linux-coco@...ts.linux.dev
Cc: Catalin Marinas <catalin.marinas@....com>,
will@...nel.org,
maz@...nel.org,
tglx@...utronix.de,
robin.murphy@....com,
suzuki.poulose@....com,
akpm@...ux-foundation.org,
jgg@...pe.ca,
steven.price@....com,
"Aneesh Kumar K.V (Arm)" <aneesh.kumar@...nel.org>
Subject: [PATCH v2 2/4] coco: guest: arm64: Fetch host IPA change alignment via RHI hostconf
- add RHI hostconf SMC IDs and helper to query version, features, and IPA change alignment
- derive the realm hypervisor page size during init and abort realm setup on invalid alignment
- make `mem_encrypt_align()` realign to the host page size for realm guests and export the helper
Signed-off-by: Aneesh Kumar K.V (Arm) <aneesh.kumar@...nel.org>
---
arch/arm64/include/asm/mem_encrypt.h | 5 +--
arch/arm64/include/asm/rhi.h | 7 ++++
arch/arm64/include/asm/rsi.h | 1 +
arch/arm64/kernel/Makefile | 2 +-
arch/arm64/kernel/rhi.c | 54 ++++++++++++++++++++++++++++
arch/arm64/kernel/rsi.c | 13 +++++++
arch/arm64/mm/mem_encrypt.c | 8 +++++
7 files changed, 85 insertions(+), 5 deletions(-)
create mode 100644 arch/arm64/kernel/rhi.c
diff --git a/arch/arm64/include/asm/mem_encrypt.h b/arch/arm64/include/asm/mem_encrypt.h
index b7ac143b81ce..06d3c30159a2 100644
--- a/arch/arm64/include/asm/mem_encrypt.h
+++ b/arch/arm64/include/asm/mem_encrypt.h
@@ -18,10 +18,7 @@ int set_memory_decrypted(unsigned long addr, int numpages);
bool force_dma_unencrypted(struct device *dev);
#define mem_encrypt_align mem_encrypt_align
-static inline size_t mem_encrypt_align(size_t size)
-{
- return size;
-}
+size_t mem_encrypt_align(size_t size);
int realm_register_memory_enc_ops(void);
diff --git a/arch/arm64/include/asm/rhi.h b/arch/arm64/include/asm/rhi.h
index a4f56f536876..414d9eab7f65 100644
--- a/arch/arm64/include/asm/rhi.h
+++ b/arch/arm64/include/asm/rhi.h
@@ -86,4 +86,11 @@ enum rhi_tdi_state {
#define __REC_EXIT_DA_VDEV_MAP 0x6
#define __RHI_DA_VDEV_SET_TDI_STATE 0x7
+unsigned long rhi_get_ipa_change_alignment(void);
+#define RHI_HOSTCONF_VER_1_0 0x10000
+#define RHI_HOSTCONF_VERSION SMC_RHI_CALL(0x004E)
+
+#define __RHI_HOSTCONF_GET_IPA_CHANGE_ALIGNMENT BIT(0)
+#define RHI_HOSTCONF_FEATURES SMC_RHI_CALL(0x004F)
+#define RHI_HOSTCONF_GET_IPA_CHANGE_ALIGNMENT SMC_RHI_CALL(0x0050)
#endif
diff --git a/arch/arm64/include/asm/rsi.h b/arch/arm64/include/asm/rsi.h
index c197bcc50239..2781d89827eb 100644
--- a/arch/arm64/include/asm/rsi.h
+++ b/arch/arm64/include/asm/rsi.h
@@ -79,5 +79,6 @@ static inline int rsi_set_memory_range_shared(phys_addr_t start,
}
bool rsi_has_da_feature(void);
+unsigned long realm_get_hyp_pagesize(void);
#endif /* __ASM_RSI_H_ */
diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
index 76f32e424065..fcb67f50ea89 100644
--- a/arch/arm64/kernel/Makefile
+++ b/arch/arm64/kernel/Makefile
@@ -34,7 +34,7 @@ obj-y := debug-monitors.o entry.o irq.o fpsimd.o \
cpufeature.o alternative.o cacheinfo.o \
smp.o smp_spin_table.o topology.o smccc-call.o \
syscall.o proton-pack.o idle.o patching.o pi/ \
- rsi.o jump_label.o
+ rsi.o jump_label.o rhi.o
obj-$(CONFIG_COMPAT) += sys32.o signal32.o \
sys_compat.o
diff --git a/arch/arm64/kernel/rhi.c b/arch/arm64/kernel/rhi.c
new file mode 100644
index 000000000000..63360ed392e4
--- /dev/null
+++ b/arch/arm64/kernel/rhi.c
@@ -0,0 +1,54 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2025 ARM Ltd.
+ */
+
+#include <asm/rsi.h>
+#include <asm/rhi.h>
+
+/* we need an aligned rhicall for rsi_host_call. slab is not yet ready */
+static struct rsi_host_call hyp_pagesize_rhicall;
+unsigned long rhi_get_ipa_change_alignment(void)
+{
+ long ret;
+ unsigned long ipa_change_align;
+
+ hyp_pagesize_rhicall.imm = 0;
+ hyp_pagesize_rhicall.gprs[0] = RHI_HOSTCONF_VERSION;
+ ret = rsi_host_call(&hyp_pagesize_rhicall);
+ if (ret != RSI_SUCCESS)
+ goto err_out;
+
+ if (hyp_pagesize_rhicall.gprs[0] != RHI_HOSTCONF_VER_1_0)
+ goto err_out;
+
+ hyp_pagesize_rhicall.imm = 0;
+ hyp_pagesize_rhicall.gprs[0] = RHI_HOSTCONF_FEATURES;
+ ret = rsi_host_call(&hyp_pagesize_rhicall);
+ if (ret != RSI_SUCCESS)
+ goto err_out;
+
+ if (!(hyp_pagesize_rhicall.gprs[0] & __RHI_HOSTCONF_GET_IPA_CHANGE_ALIGNMENT))
+ goto err_out;
+
+ hyp_pagesize_rhicall.imm = 0;
+ hyp_pagesize_rhicall.gprs[0] = RHI_HOSTCONF_GET_IPA_CHANGE_ALIGNMENT;
+ ret = rsi_host_call(&hyp_pagesize_rhicall);
+ if (ret != RSI_SUCCESS)
+ goto err_out;
+
+ ipa_change_align = hyp_pagesize_rhicall.gprs[0];
+ /* This error needs special handling in the caller */
+ if (ipa_change_align & (SZ_4K - 1))
+ return 0;
+
+ return ipa_change_align;
+
+err_out:
+ /*
+ * For failure condition assume host is built with 4K page size
+ * and hence ipa change alignment can be guest PAGE_SIZE.
+ */
+ return PAGE_SIZE;
+}
+
diff --git a/arch/arm64/kernel/rsi.c b/arch/arm64/kernel/rsi.c
index aae24009cadb..57de4103be03 100644
--- a/arch/arm64/kernel/rsi.c
+++ b/arch/arm64/kernel/rsi.c
@@ -13,9 +13,12 @@
#include <asm/io.h>
#include <asm/mem_encrypt.h>
#include <asm/rsi.h>
+#include <asm/rhi.h>
static struct realm_config config;
static u64 rsi_feat_reg0;
+static unsigned long ipa_change_alignment = PAGE_SIZE;
+
unsigned long prot_ns_shared;
EXPORT_SYMBOL(prot_ns_shared);
@@ -147,6 +150,11 @@ static int realm_ioremap_hook(phys_addr_t phys, size_t size, pgprot_t *prot)
return 0;
}
+unsigned long realm_get_hyp_pagesize(void)
+{
+ return ipa_change_alignment;
+}
+
void __init arm64_rsi_init(void)
{
static_branch_enable(&rsi_init_call_done);
@@ -158,6 +166,11 @@ void __init arm64_rsi_init(void)
if (WARN_ON(rsi_get_realm_config(&config)))
return;
+ ipa_change_alignment = rhi_get_ipa_change_alignment();
+ /* If we don't get a correct alignment response, don't enable realm */
+ if (!ipa_change_alignment)
+ return;
+
if (WARN_ON(rsi_features(0, &rsi_feat_reg0)))
return;
diff --git a/arch/arm64/mm/mem_encrypt.c b/arch/arm64/mm/mem_encrypt.c
index deb364eadd47..6937f753e89d 100644
--- a/arch/arm64/mm/mem_encrypt.c
+++ b/arch/arm64/mm/mem_encrypt.c
@@ -64,3 +64,11 @@ bool force_dma_unencrypted(struct device *dev)
return is_realm_world();
}
EXPORT_SYMBOL_GPL(force_dma_unencrypted);
+
+size_t mem_encrypt_align(size_t size)
+{
+ if (is_realm_world())
+ return ALIGN(size, realm_get_hyp_pagesize());
+ return size;
+}
+EXPORT_SYMBOL_GPL(mem_encrypt_align);
--
2.43.0
Powered by blists - more mailing lists