[PATCH v11 5/6] KVM: arm64: Mask response to FFA_FEATURE call
From: Per Larsen via B4 Relay <devnull+perlarsen.google.com@kernel.org>
Date: 2025-08-20 01:10:12
Also in:
b4-sent, kvmarm, lkml
Subsystem:
arm64 port (aarch64 architecture), firmware framework for armv8-a, kernel virtual machine for arm64 (kvm/arm64), the rest · Maintainers:
Catalin Marinas, Will Deacon, Sudeep Holla, Marc Zyngier, Oliver Upton, Linus Torvalds
From: Per Larsen <redacted> The minimum size and alignment boundary for FFA_RXTX_MAP is returned in bit[1:0]. Mask off any other bits in w2 when reading the minimum buffer size in hyp_ffa_post_init. Acked-by: Will Deacon <will@kernel.org> Signed-off-by: Per Larsen <redacted> --- arch/arm64/kvm/hyp/nvhe/ffa.c | 2 +- include/linux/arm_ffa.h | 1 + 2 files changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/kvm/hyp/nvhe/ffa.c b/arch/arm64/kvm/hyp/nvhe/ffa.c
index 96109aa99c48741e45a2b85d8e7bf26440597398..a8ec1a94f3f8a86551895f4606918246c4ac1f39 100644
--- a/arch/arm64/kvm/hyp/nvhe/ffa.c
+++ b/arch/arm64/kvm/hyp/nvhe/ffa.c@@ -739,7 +739,7 @@ static int hyp_ffa_post_init(void) if (res.a0 != FFA_SUCCESS) return -EOPNOTSUPP; - switch (res.a2) { + switch (res.a2 & FFA_FEAT_RXTX_MIN_SZ_MASK) { case FFA_FEAT_RXTX_MIN_SZ_4K: min_rxtx_sz = SZ_4K; break;
diff --git a/include/linux/arm_ffa.h b/include/linux/arm_ffa.h
index e1634897e159cdc208931938649eb0fb04d5a070..cd7ee4df9045dceca1c4e0dca2d533b770b1b056 100644
--- a/include/linux/arm_ffa.h
+++ b/include/linux/arm_ffa.h@@ -128,6 +128,7 @@ #define FFA_FEAT_RXTX_MIN_SZ_4K 0 #define FFA_FEAT_RXTX_MIN_SZ_64K 1 #define FFA_FEAT_RXTX_MIN_SZ_16K 2 +#define FFA_FEAT_RXTX_MIN_SZ_MASK GENMASK(1, 0) /* FFA Bus/Device/Driver related */ struct ffa_device {
--
2.51.0.rc1.167.g924127e9c0-goog