fix(rmmd/sve): enable/disable SVE/FPU for Realms
This patch enable/disable SVE/FPU for Realms depending
upon it's state in NS.
When this feature is enabled, traps to EL3 on SVE/FPU access from
Realms are disabled. However, RMM must ensure that the Realm <-> NS
SVE/FPU registers are not corrupted by each other and Realms do
not leak information to NS.
Change-Id: I0a27a055787976507017b72879ba6458f066624e
Signed-off-by: Subhasish Ghosh <subhasish.ghosh@arm.com>
diff --git a/services/std_svc/rmmd/rmmd_main.c b/services/std_svc/rmmd/rmmd_main.c
index e9004c7..c4ea706 100644
--- a/services/std_svc/rmmd/rmmd_main.c
+++ b/services/std_svc/rmmd/rmmd_main.c
@@ -30,6 +30,7 @@
#include <services/rmi_svc.h>
#include <services/rmmd_svc.h>
#include <smccc_helpers.h>
+#include <lib/extensions/sve.h>
#include "rmmd_initial_context.h"
#include "rmmd_private.h"
@@ -112,6 +113,26 @@
}
/*******************************************************************************
+ * Enable architecture extensions on first entry to Realm world.
+ ******************************************************************************/
+static void manage_extensions_realm(cpu_context_t *ctx)
+{
+#if ENABLE_SVE_FOR_NS
+ /*
+ * Enable SVE and FPU in realm context when it is enabled for NS.
+ * Realm manager must ensure that the SVE and FPU register
+ * contexts are properly managed.
+ */
+ sve_enable(ctx);
+#else
+ /*
+ * Disable SVE and FPU in realm context when it is disabled for NS.
+ */
+ sve_disable(ctx);
+#endif /* ENABLE_SVE_FOR_NS */
+}
+
+/*******************************************************************************
* Jump to the RMM for the first time.
******************************************************************************/
static int32_t rmm_init(void)
@@ -124,6 +145,9 @@
INFO("RMM init start.\n");
ctx->state = RMM_STATE_RESET;
+ /* Enable architecture extensions */
+ manage_extensions_realm(&ctx->cpu_ctx);
+
/* Initialize RMM EL2 context. */
rmm_el2_context_init(&ctx->cpu_ctx.el2_sysregs_ctx);
@@ -281,6 +305,9 @@
/* Initialise RMM context with this entry point information */
cm_setup_context(&ctx->cpu_ctx, rmm_ep_info);
+ /* Enable architecture extensions */
+ manage_extensions_realm(&ctx->cpu_ctx);
+
/* Initialize RMM EL2 context. */
rmm_el2_context_init(&ctx->cpu_ctx.el2_sysregs_ctx);