From 449dca6ac93afbed1af00b6a29c9729f6cb18c35 Mon Sep 17 00:00:00 2001 From: Marcin Juszkiewicz Date: Wed, 23 Oct 2024 13:38:20 +0200 Subject: pcie: enable Extended tag field support >From what I read PCI has 32 transactions, PCI Express devices can handle 256 with Extended tag enabled (spec mentions also larger values but I lack PCIe knowledge). QEMU leaves 'Extended tag field' with 0 as value: Capabilities: [e0] Express (v1) Root Complex Integrated Endpoint, IntMsgNum 0 DevCap: MaxPayload 128 bytes, PhantFunc 0 ExtTag- RBE+ FLReset- TEE-IO- SBSA ACS has test 824 which checks for PCIe device capabilities. BSA specification [1] (SBSA is on top of BSA) in section F.3.2 lists expected values for Device Capabilities Register: Device Capabilities Register Requirement Role based error reporting RCEC and RCiEP: Hardwired to 1 Endpoint L0s acceptable latency RCEC and RCiEP: Hardwired to 0 L1 acceptable latency RCEC and RCiEP: Hardwired to 0 Captured slot power limit scale RCEC and RCiEP: Hardwired to 0 Captured slot power limit value RCEC and RCiEP: Hardwired to 0 Max payload size value must be compliant with PCIe spec Phantom functions RCEC and RCiEP: Recommendation is to hardwire this bit to 0. Extended tag field Hardwired to 1 1. https://developer.arm.com/documentation/den0094/c/ This change enables Extended tag field. All versioned platforms should have it disabled for older versions (tested with Arm/virt). Signed-off-by: Marcin Juszkiewicz Message-Id: <20241023113820.486017-1-marcin.juszkiewicz@linaro.org> Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- hw/core/machine.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'hw/core') diff --git a/hw/core/machine.c b/hw/core/machine.c index adaba17..8ccc740 100644 --- a/hw/core/machine.c +++ b/hw/core/machine.c @@ -34,7 +34,9 @@ #include "hw/virtio/virtio-iommu.h" #include "audio/audio.h" -GlobalProperty hw_compat_9_1[] = {}; +GlobalProperty hw_compat_9_1[] = { + { TYPE_PCI_DEVICE, "x-pcie-ext-tag", "false" }, +}; const size_t hw_compat_9_1_len = G_N_ELEMENTS(hw_compat_9_1); GlobalProperty hw_compat_9_0[] = { -- cgit v1.1