From 164e2ab0f68f483440d1d0c2ea9c154926c36e83 Mon Sep 17 00:00:00 2001 From: Yuchao Date: Wed, 5 Aug 2026 04:47:21 +0800 Subject: [PATCH] Fix BAR1 P2P on display-attached GPUs --- src/nvidia/src/kernel/gpu/bus/kern_bus.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/src/nvidia/src/kernel/gpu/bus/kern_bus.c b/src/nvidia/src/kernel/gpu/bus/kern_bus.c index d3d45ec586..52a50ad874 100644 --- a/src/nvidia/src/kernel/gpu/bus/kern_bus.c +++ b/src/nvidia/src/kernel/gpu/bus/kern_bus.c @@ -194,7 +194,12 @@ kbusInitRegistryOverrides(OBJGPU *pGpu, KernelBus *pKernelBus) } else { - pKernelBus->staticBar1ForceType = NV_REG_STR_RM_FORCE_STATIC_BAR1_AUTO; + // This branch enables BAR1 P2P on consumer Blackwell GPUs. The auto + // policy can reject a display-driving 32 GB BAR because its conservative + // sizing includes worst-case UserD/doorbell overhead in addition to the + // console reservation. Force the static mapping by default; the force + // path still verifies that the client-visible FB mapping fits in BAR1. + pKernelBus->staticBar1ForceType = NV_REG_STR_RM_FORCE_STATIC_BAR1_ENABLE; } //