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From: Suzuki K Poulose <suzuki.poulose@arm.com>
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Subject: [RFC kvmtool 28/31] arm64: realm: Enforce virtio F_ACCESS_PLATFORM flag
Date: Fri, 27 Jan 2023 11:39:29 +0000
Message-Id: <20230127113932.166089-29-suzuki.poulose@arm.com>
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For realms, force the F_ACCESS_PLATFORM flag to ensure DMA-APIs
are triggered for virtio in Linux

Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
 arm/aarch64/kvm.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/arm/aarch64/kvm.c b/arm/aarch64/kvm.c
index a4664237..1f3a0def 100644
--- a/arm/aarch64/kvm.c
+++ b/arm/aarch64/kvm.c
@@ -5,6 +5,7 @@
 #include <linux/byteorder.h>
 #include <linux/cpumask.h>
 #include <linux/sizes.h>
+#include <linux/virtio_config.h>
 
 #include <kvm/util.h>
 
@@ -237,5 +238,10 @@ void kvm__arch_enable_mte(struct kvm *kvm)
 
 u64 kvm__arch_get_virtio_host_features(struct kvm *kvm)
 {
-	return 0;
+	u64 features = 0;
+
+	/* Enforce F_ACCESS_PLATFORM for Realms */
+	if (kvm->cfg.arch.is_realm)
+		features |= (1ULL << VIRTIO_F_ACCESS_PLATFORM);
+	return features;
 }
-- 
2.34.1