From 449dca6ac93afbed1af00b6a29c9729f6cb18c35 Mon Sep 17 00:00:00 2001 From: Marcin Juszkiewicz Date: Wed, 23 Oct 2024 13:38:20 +0200 Subject: [PATCH] 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 +++- hw/pci/pci.c | 2 ++ hw/pci/pcie.c | 8 +++++++- include/hw/pci/pci.h | 2 ++ 4 files changed, 14 insertions(+), 2 deletions(-) diff --git a/hw/core/machine.c b/hw/core/machine.c index adaba17eba..8ccc74067a 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[] = { diff --git a/hw/pci/pci.c b/hw/pci/pci.c index 0b6bdaa0d7..1416ae202c 100644 --- a/hw/pci/pci.c +++ b/hw/pci/pci.c @@ -100,6 +100,8 @@ static Property pci_props[] = { QEMU_PCIE_ARI_NEXTFN_1_BITNR, false), DEFINE_PROP_SIZE32("x-max-bounce-buffer-size", PCIDevice, max_bounce_buffer_size, DEFAULT_MAX_BOUNCE_BUFFER_SIZE), + DEFINE_PROP_BIT("x-pcie-ext-tag", PCIDevice, cap_present, + QEMU_PCIE_EXT_TAG_BITNR, true), { .name = "busnr", .info = &prop_pci_busnr }, DEFINE_PROP_END_OF_LIST() }; diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c index 2738dbb28d..0b455c8654 100644 --- a/hw/pci/pcie.c +++ b/hw/pci/pcie.c @@ -86,7 +86,13 @@ pcie_cap_v1_fill(PCIDevice *dev, uint8_t port, uint8_t type, uint8_t version) * Specification, Revision 1.1., or subsequent PCI Express Base * Specification revisions. */ - pci_set_long(exp_cap + PCI_EXP_DEVCAP, PCI_EXP_DEVCAP_RBER); + uint32_t devcap = PCI_EXP_DEVCAP_RBER; + + if (dev->cap_present & QEMU_PCIE_EXT_TAG) { + devcap = PCI_EXP_DEVCAP_RBER | PCI_EXP_DEVCAP_EXT_TAG; + } + + pci_set_long(exp_cap + PCI_EXP_DEVCAP, devcap); pci_set_long(exp_cap + PCI_EXP_LNKCAP, (port << PCI_EXP_LNKCAP_PN_SHIFT) | diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h index 35d4fe0bbf..38ffa7bcee 100644 --- a/include/hw/pci/pci.h +++ b/include/hw/pci/pci.h @@ -214,6 +214,8 @@ enum { QEMU_PCIE_ERR_UNC_MASK = (1 << QEMU_PCIE_ERR_UNC_MASK_BITNR), #define QEMU_PCIE_ARI_NEXTFN_1_BITNR 12 QEMU_PCIE_ARI_NEXTFN_1 = (1 << QEMU_PCIE_ARI_NEXTFN_1_BITNR), +#define QEMU_PCIE_EXT_TAG_BITNR 13 + QEMU_PCIE_EXT_TAG = (1 << QEMU_PCIE_EXT_TAG_BITNR), }; typedef struct PCIINTxRoute {