On 10/5/24 12:43 AM, Steven Price wrote:
From: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
Instead of marking every MMIO as shared, check if the given region is
"Protected" and apply the permissions accordingly.
Signed-off-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
Signed-off-by: Steven Price <steven.price@xxxxxxx>
---
New patch for v5
---
arch/arm64/kernel/rsi.c | 15 +++++++++++++++
1 file changed, 15 insertions(+)
With the following potential issue addressed:
Reviewed-by: Gavin Shan <gshan@xxxxxxxxxx>
diff --git a/arch/arm64/kernel/rsi.c b/arch/arm64/kernel/rsi.c
index d7bba4cee627..f1add76f89ce 100644
--- a/arch/arm64/kernel/rsi.c
+++ b/arch/arm64/kernel/rsi.c
@@ -6,6 +6,8 @@
#include <linux/jump_label.h>
#include <linux/memblock.h>
#include <linux/psci.h>
+
+#include <asm/io.h>
#include <asm/rsi.h>
struct realm_config config;
@@ -92,6 +94,16 @@ bool arm64_is_protected_mmio(phys_addr_t base, size_t size)
}
EXPORT_SYMBOL(arm64_is_protected_mmio);
+static int realm_ioremap_hook(phys_addr_t phys, size_t size, pgprot_t *prot)
+{
+ if (arm64_is_protected_mmio(phys, size))
+ *prot = pgprot_encrypted(*prot);
+ else
+ *prot = pgprot_decrypted(*prot);
+
+ return 0;
+}
+
We probably need arm64_is_mmio_private() here, meaning arm64_is_protected_mmio() isn't
sufficient to avoid invoking SMCCC call SMC_RSI_IPA_STATE_GET in a regular guest where
realm capability isn't present.
void __init arm64_rsi_init(void)
{
if (arm_smccc_1_1_get_conduit() != SMCCC_CONDUIT_SMC)
@@ -102,6 +114,9 @@ void __init arm64_rsi_init(void)
return;
prot_ns_shared = BIT(config.ipa_bits - 1);
+ if (arm64_ioremap_prot_hook_register(realm_ioremap_hook))
+ return;
+
arm64_rsi_setup_memory();
static_branch_enable(&rsi_present);
Thanks,
Gavin
