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* [PATCH v1 00/10] Add Xue - console over USB 3 Debug Capability
@ 2022-06-07 14:30 Marek Marczykowski-Górecki
  2022-06-07 14:30 ` [PATCH v1 01/10] drivers/char: Add support for Xue USB3 debugger Marek Marczykowski-Górecki
                   ` (11 more replies)
  0 siblings, 12 replies; 23+ messages in thread
From: Marek Marczykowski-Górecki @ 2022-06-07 14:30 UTC (permalink / raw)
  To: xen-devel
  Cc: Marek Marczykowski-Górecki, Andrew Cooper, George Dunlap,
	Jan Beulich, Julien Grall, Stefano Stabellini, Wei Liu,
	Roger Pau Monné,
	Paul Durrant, Kevin Tian, Connor Davis

This is integration of https://github.com/connojd/xue into mainline Xen.
This patch series includes several patches that I made in the process, some are
very loosely related.

The driver developed by Connor supports output-only console via USB3 debug
capability. The capability is designed to operate mostly independently of
normal XHCI driver, so this patch series allows dom0 to drive standard USB3
controller part, while Xen uses DbC for console output.

Changes since RFC:
 - move the driver to xue.c, remove non-Xen parts, remove now unneeded abstraction
 - adjust for Xen code style
 - build for x86 only
 - drop patch hidding the device from dom0

Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: George Dunlap <george.dunlap@citrix.com>
Cc: Jan Beulich <jbeulich@suse.com>
Cc: Julien Grall <julien@xen.org>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Wei Liu <wl@xen.org>
Cc: "Roger Pau Monné" <roger.pau@citrix.com>
Cc: Paul Durrant <paul@xen.org>
Cc: Kevin Tian <kevin.tian@intel.com>
Cc: Connor Davis <connojdavis@gmail.com>

Connor Davis (1):
  drivers/char: Add support for Xue USB3 debugger

Marek Marczykowski-Górecki (9):
  xue: reset XHCI ports when initializing dbc
  xue: add support for selecting specific xhci
  ehci-dbgp: fix selecting n-th ehci controller
  console: support multiple serial console simultaneously
  IOMMU: add common API for device reserved memory
  IOMMU/VT-d: wire common device reserved memory API
  IOMMU/AMD: wire common device reserved memory API
  xue: mark DMA buffers as reserved for the device
  xue: allow driving the rest of XHCI by a domain while Xen uses DbC

 docs/misc/xen-command-line.pandoc        |    5 +-
 xen/arch/x86/Kconfig                     |    1 +-
 xen/arch/x86/include/asm/fixmap.h        |    4 +-
 xen/arch/x86/setup.c                     |    1 +-
 xen/drivers/char/Kconfig                 |    7 +-
 xen/drivers/char/Makefile                |    1 +-
 xen/drivers/char/console.c               |   58 +-
 xen/drivers/char/ehci-dbgp.c             |    2 +-
 xen/drivers/char/xue.c                   | 1089 +++++++++++++++++++++++-
 xen/drivers/passthrough/amd/iommu_acpi.c |   16 +-
 xen/drivers/passthrough/iommu.c          |   40 +-
 xen/drivers/passthrough/vtd/dmar.c       |  203 ++--
 xen/include/xen/iommu.h                  |   11 +-
 xen/include/xen/serial.h                 |    1 +-
 14 files changed, 1342 insertions(+), 97 deletions(-)
 create mode 100644 xen/drivers/char/xue.c

base-commit: 49dd52fb1311dadab29f6634d0bc1f4c022c357a
-- 
git-series 0.9.1


^ permalink raw reply	[flat|nested] 23+ messages in thread

* [PATCH v1 01/10] drivers/char: Add support for Xue USB3 debugger
  2022-06-07 14:30 [PATCH v1 00/10] Add Xue - console over USB 3 Debug Capability Marek Marczykowski-Górecki
@ 2022-06-07 14:30 ` Marek Marczykowski-Górecki
  2022-06-15 14:25   ` Jan Beulich
  2022-06-07 14:30 ` [PATCH v1 02/10] xue: reset XHCI ports when initializing dbc Marek Marczykowski-Górecki
                   ` (10 subsequent siblings)
  11 siblings, 1 reply; 23+ messages in thread
From: Marek Marczykowski-Górecki @ 2022-06-07 14:30 UTC (permalink / raw)
  To: xen-devel
  Cc: Marek Marczykowski-Górecki, Connor Davis, Jan Beulich,
	Andrew Cooper, Roger Pau Monné,
	Wei Liu, George Dunlap, Julien Grall, Stefano Stabellini

From: Connor Davis <davisc@ainfosec.com>

[Connor]
Xue is a cross-platform USB 3 debugger that drives the Debug
Capability (DbC) of xHCI-compliant host controllers. This patch
implements the operations needed for xue to initialize the host
controller's DbC and communicate with it. It also implements a struct
uart_driver that uses xue as a backend. Note that only target -> host
communication is supported for now. To use Xue as a console, add
'console=dbgp dbgp=xue' to the command line.

[Marek]
The Xue driver is taken from https://github.com/connojd/xue and heavily
refactored to fit into Xen code base. Major changes include:
- drop support for non-Xen systems
- drop xue_ops abstraction
- use Xen's native helper functions for PCI access
- move all the code to xue.c, drop "inline"
- build for x86 only
- annotate functions with cf_check
- adjust for Xen's code style

Signed-off-by: Connor Davis <davisc@ainfosec.com>
Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
---
 xen/arch/x86/Kconfig              |   1 +-
 xen/arch/x86/include/asm/fixmap.h |   4 +-
 xen/arch/x86/setup.c              |   1 +-
 xen/drivers/char/Kconfig          |   7 +-
 xen/drivers/char/Makefile         |   1 +-
 xen/drivers/char/xue.c            | 957 +++++++++++++++++++++++++++++++-
 xen/include/xen/serial.h          |   1 +-
 7 files changed, 972 insertions(+)
 create mode 100644 xen/drivers/char/xue.c

diff --git a/xen/arch/x86/Kconfig b/xen/arch/x86/Kconfig
index 06d6fbc86478..9260f464d478 100644
--- a/xen/arch/x86/Kconfig
+++ b/xen/arch/x86/Kconfig
@@ -13,6 +13,7 @@ config X86
 	select HAS_COMPAT
 	select HAS_CPUFREQ
 	select HAS_EHCI
+	select HAS_XHCI
 	select HAS_EX_TABLE
 	select HAS_FAST_MULTIPLY
 	select HAS_IOPORTS
diff --git a/xen/arch/x86/include/asm/fixmap.h b/xen/arch/x86/include/asm/fixmap.h
index 20746afd0a2a..bc39ffe896b1 100644
--- a/xen/arch/x86/include/asm/fixmap.h
+++ b/xen/arch/x86/include/asm/fixmap.h
@@ -25,6 +25,8 @@
 #include <asm/msi.h>
 #include <acpi/apei.h>
 
+#define MAX_XHCI_PAGES 16
+
 /*
  * Here we define all the compile-time 'special' virtual
  * addresses. The point is to have a constant address at
@@ -43,6 +45,8 @@ enum fixed_addresses {
     FIX_COM_BEGIN,
     FIX_COM_END,
     FIX_EHCI_DBGP,
+    FIX_XHCI_BEGIN,
+    FIX_XHCI_END = FIX_XHCI_BEGIN + MAX_XHCI_PAGES - 1,
 #ifdef CONFIG_XEN_GUEST
     FIX_PV_CONSOLE,
     FIX_XEN_SHARED_INFO,
diff --git a/xen/arch/x86/setup.c b/xen/arch/x86/setup.c
index 53a73010e029..801081befa78 100644
--- a/xen/arch/x86/setup.c
+++ b/xen/arch/x86/setup.c
@@ -946,6 +946,7 @@ void __init noreturn __start_xen(unsigned long mbi_p)
     ns16550.irq     = 3;
     ns16550_init(1, &ns16550);
     ehci_dbgp_init();
+    xue_uart_init();
     console_init_preirq();
 
     if ( pvh_boot )
diff --git a/xen/drivers/char/Kconfig b/xen/drivers/char/Kconfig
index e5f7b1d8eb8a..55d35af960e5 100644
--- a/xen/drivers/char/Kconfig
+++ b/xen/drivers/char/Kconfig
@@ -74,3 +74,10 @@ config HAS_EHCI
 	help
 	  This selects the USB based EHCI debug port to be used as a UART. If
 	  you have an x86 based system with USB, say Y.
+
+config HAS_XHCI
+	bool
+	depends on X86
+	help
+      This selects the USB based XHCI debug capability to be used as a UART. If
+      you have an x86 based system with USB3, say Y.
diff --git a/xen/drivers/char/Makefile b/xen/drivers/char/Makefile
index 14e67cf072d7..bda1e44d3f39 100644
--- a/xen/drivers/char/Makefile
+++ b/xen/drivers/char/Makefile
@@ -8,6 +8,7 @@ obj-$(CONFIG_HAS_MVEBU) += mvebu-uart.o
 obj-$(CONFIG_HAS_OMAP) += omap-uart.o
 obj-$(CONFIG_HAS_SCIF) += scif-uart.o
 obj-$(CONFIG_HAS_EHCI) += ehci-dbgp.o
+obj-$(CONFIG_HAS_XHCI) += xue.o
 obj-$(CONFIG_HAS_IMX_LPUART) += imx-lpuart.o
 obj-$(CONFIG_ARM) += arm-uart.o
 obj-y += serial.o
diff --git a/xen/drivers/char/xue.c b/xen/drivers/char/xue.c
new file mode 100644
index 000000000000..e95dd09d39a8
--- /dev/null
+++ b/xen/drivers/char/xue.c
@@ -0,0 +1,957 @@
+/*
+ * drivers/char/xue.c
+ *
+ * Xen port for the xue debugger
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Copyright (c) 2019 Assured Information Security.
+ */
+
+#include <xen/delay.h>
+#include <xen/types.h>
+#include <asm/string.h>
+#include <asm/system.h>
+#include <xen/serial.h>
+#include <xen/timer.h>
+#include <xen/param.h>
+#include <asm/fixmap.h>
+#include <asm/io.h>
+#include <xen/mm.h>
+
+#define XUE_POLL_INTERVAL 100 /* us */
+
+#define XUE_PAGE_SIZE 4096ULL
+
+/* Supported xHC PCI configurations */
+#define XUE_XHC_CLASSC 0xC0330ULL
+
+/* DbC idVendor and idProduct */
+#define XUE_DBC_VENDOR 0x1D6B
+#define XUE_DBC_PRODUCT 0x0010
+#define XUE_DBC_PROTOCOL 0x0000
+
+/* DCCTRL fields */
+#define XUE_CTRL_DCR 0
+#define XUE_CTRL_HOT 2
+#define XUE_CTRL_HIT 3
+#define XUE_CTRL_DRC 4
+#define XUE_CTRL_DCE 31
+
+/* DCPORTSC fields */
+#define XUE_PSC_PED 1
+#define XUE_PSC_CSC 17
+#define XUE_PSC_PRC 21
+#define XUE_PSC_PLC 22
+#define XUE_PSC_CEC 23
+
+#define XUE_PSC_ACK_MASK                                                       \
+    ((1UL << XUE_PSC_CSC) | (1UL << XUE_PSC_PRC) | (1UL << XUE_PSC_PLC) |      \
+     (1UL << XUE_PSC_CEC))
+
+#define xue_debug(...) printk("xue debug: " __VA_ARGS__)
+#define xue_alert(...) printk("xue alert: " __VA_ARGS__)
+#define xue_error(...) printk("xue error: " __VA_ARGS__)
+
+/******************************************************************************
+ * TRB ring (summarized from the manual):
+ *
+ * TRB rings are circular queues of TRBs shared between the xHC and the driver.
+ * Each ring has one producer and one consumer. The DbC has one event
+ * ring and two transfer rings; one IN and one OUT.
+ *
+ * The DbC hardware is the producer on the event ring, and
+ * xue is the consumer. This means that event TRBs are read-only from
+ * the xue.
+ *
+ * OTOH, xue is the producer of transfer TRBs on the two transfer
+ * rings, so xue enqueues transfers, and the hardware dequeues
+ * them. The dequeue pointer of a transfer ring is read by
+ * xue by examining the latest transfer event TRB on the event ring. The
+ * transfer event TRB contains the address of the transfer TRB that generated
+ * the event.
+ *
+ * To make each transfer ring circular, the last TRB must be a link TRB, which
+ * points to the beginning of the next queue. Note that this implementation
+ * does not support multiple segments, so each link TRB points back to the
+ * beginning of its own segment.
+ ******************************************************************************/
+
+/* TRB types */
+enum {
+    xue_trb_norm = 1,
+    xue_trb_link = 6,
+    xue_trb_tfre = 32,
+    xue_trb_psce = 34
+};
+
+/* TRB completion codes */
+enum { xue_trb_cc_success = 1, xue_trb_cc_trb_err = 5 };
+
+/* DbC endpoint types */
+enum { xue_ep_bulk_out = 2, xue_ep_bulk_in = 6 };
+
+/* DMA/MMIO structures */
+#pragma pack(push, 1)
+struct xue_trb {
+    uint64_t params;
+    uint32_t status;
+    uint32_t ctrl;
+};
+
+struct xue_erst_segment {
+    uint64_t base;
+    uint16_t size;
+    uint8_t rsvdz[6];
+};
+
+#define XUE_CTX_SIZE 16
+#define XUE_CTX_BYTES (XUE_CTX_SIZE * 4)
+
+struct xue_dbc_ctx {
+    uint32_t info[XUE_CTX_SIZE];
+    uint32_t ep_out[XUE_CTX_SIZE];
+    uint32_t ep_in[XUE_CTX_SIZE];
+};
+
+struct xue_dbc_reg {
+    uint32_t id;
+    uint32_t db;
+    uint32_t erstsz;
+    uint32_t rsvdz;
+    uint64_t erstba;
+    uint64_t erdp;
+    uint32_t ctrl;
+    uint32_t st;
+    uint32_t portsc;
+    uint32_t rsvdp;
+    uint64_t cp;
+    uint32_t ddi1;
+    uint32_t ddi2;
+};
+#pragma pack(pop)
+
+#define XUE_TRB_MAX_TFR (XUE_PAGE_SIZE << 4)
+#define XUE_TRB_PER_PAGE (XUE_PAGE_SIZE / sizeof(struct xue_trb))
+
+/* Defines the size in bytes of TRB rings as 2^XUE_TRB_RING_ORDER * 4096 */
+#ifndef XUE_TRB_RING_ORDER
+#define XUE_TRB_RING_ORDER 4
+#endif
+#define XUE_TRB_RING_CAP (XUE_TRB_PER_PAGE * (1ULL << XUE_TRB_RING_ORDER))
+#define XUE_TRB_RING_BYTES (XUE_TRB_RING_CAP * sizeof(struct xue_trb))
+#define XUE_TRB_RING_MASK (XUE_TRB_RING_BYTES - 1U)
+
+struct xue_trb_ring {
+    struct xue_trb *trb; /* Array of TRBs */
+    uint32_t enq; /* The offset of the enqueue ptr */
+    uint32_t deq; /* The offset of the dequeue ptr */
+    uint8_t cyc; /* Cycle state toggled on each wrap-around */
+    uint8_t db; /* Doorbell target */
+};
+
+#define XUE_DB_OUT 0x0
+#define XUE_DB_IN 0x1
+#define XUE_DB_INVAL 0xFF
+
+/* Defines the size in bytes of work rings as 2^XUE_WORK_RING_ORDER * 4096 */
+#ifndef XUE_WORK_RING_ORDER
+#define XUE_WORK_RING_ORDER 3
+#endif
+#define XUE_WORK_RING_CAP (XUE_PAGE_SIZE * (1ULL << XUE_WORK_RING_ORDER))
+#define XUE_WORK_RING_BYTES XUE_WORK_RING_CAP
+
+#if XUE_WORK_RING_CAP > XUE_TRB_MAX_TFR
+#error "XUE_WORK_RING_ORDER must be at most 4"
+#endif
+
+struct xue_work_ring {
+    uint8_t *buf;
+    uint32_t enq;
+    uint32_t deq;
+    uint64_t dma;
+};
+
+struct xue {
+    struct xue_dbc_reg *dbc_reg;
+    struct xue_dbc_ctx *dbc_ctx;
+    struct xue_erst_segment *dbc_erst;
+    struct xue_trb_ring dbc_ering;
+    struct xue_trb_ring dbc_oring;
+    struct xue_trb_ring dbc_iring;
+    struct xue_work_ring dbc_owork;
+    char *dbc_str;
+
+    pci_sbdf_t sbdf;
+    uint64_t xhc_mmio_phys;
+    uint64_t xhc_mmio_size;
+    uint64_t xhc_dbc_offset;
+    void *xhc_mmio;
+
+    int open;
+};
+
+static void xue_sys_pause(void)
+{
+    __asm volatile("pause" ::: "memory");
+}
+
+static void *xue_sys_map_xhc(uint64_t phys, uint64_t size)
+{
+    size_t i;
+
+    if ( size != MAX_XHCI_PAGES * XUE_PAGE_SIZE )
+        return NULL;
+
+    for ( i = FIX_XHCI_END; i >= FIX_XHCI_BEGIN; i-- )
+    {
+        set_fixmap_nocache(i, phys);
+        phys += XUE_PAGE_SIZE;
+    }
+
+    /*
+     * The fixmap grows downward, so the lowest virt is
+     * at the highest index
+     */
+    return fix_to_virt(FIX_XHCI_END);
+}
+
+static void xue_flush_range(struct xue *xue, void *ptr, uint32_t bytes)
+{
+    uint32_t i;
+
+    const uint32_t clshft = 6;
+    const uint32_t clsize = (1UL << clshft);
+    const uint32_t clmask = clsize - 1;
+
+    uint32_t lines = (bytes >> clshft);
+    lines += (bytes & clmask) != 0;
+
+    for ( i = 0; i < lines; i++ )
+        clflush((void *)((uint64_t)ptr + (i * clsize)));
+}
+
+static int xue_init_xhc(struct xue *xue)
+{
+    uint32_t bar0;
+    uint64_t bar1;
+    uint64_t devfn;
+
+    /*
+     * Search PCI bus 0 for the xHC. All the host controllers supported so far
+     * are part of the chipset and are on bus 0.
+     */
+    for ( devfn = 0; devfn < 256; devfn++ ) {
+        uint32_t dev = (devfn & 0xF8) >> 3;
+        uint32_t fun = devfn & 0x07;
+        pci_sbdf_t sbdf = PCI_SBDF(0, dev, fun);
+        uint32_t hdr = pci_conf_read8(sbdf, PCI_HEADER_TYPE);
+
+        if ( hdr == 0 || hdr == 0x80 )
+        {
+            if ( (pci_conf_read32(sbdf, PCI_CLASS_REVISION) >> 8) == XUE_XHC_CLASSC )
+            {
+                xue->sbdf = sbdf;
+                break;
+            }
+        }
+    }
+
+    if ( !xue->sbdf.sbdf )
+    {
+        xue_error("Compatible xHC not found on bus 0\n");
+        return 0;
+    }
+
+    /* ...we found it, so parse the BAR and map the registers */
+    bar0 = pci_conf_read32(xue->sbdf, PCI_BASE_ADDRESS_0);
+    bar1 = pci_conf_read32(xue->sbdf, PCI_BASE_ADDRESS_1);
+
+    /* IO BARs not allowed; BAR must be 64-bit */
+    if ( (bar0 & 0x1) != 0 || ((bar0 & 0x6) >> 1) != 2 )
+        return 0;
+
+    pci_conf_write32(xue->sbdf, PCI_BASE_ADDRESS_0, 0xFFFFFFFF);
+    xue->xhc_mmio_size = ~(pci_conf_read32(xue->sbdf, PCI_BASE_ADDRESS_0) & 0xFFFFFFF0) + 1;
+    pci_conf_write32(xue->sbdf, PCI_BASE_ADDRESS_0, bar0);
+
+    xue->xhc_mmio_phys = (bar0 & 0xFFFFFFF0) | (bar1 << 32);
+    xue->xhc_mmio = xue_sys_map_xhc(xue->xhc_mmio_phys, xue->xhc_mmio_size);
+
+    return xue->xhc_mmio != NULL;
+}
+
+/**
+ * The first register of the debug capability is found by traversing the
+ * host controller's capability list (xcap) until a capability
+ * with ID = 0xA is found. The xHCI capability list begins at address
+ * mmio + (HCCPARAMS1[31:16] << 2)
+ */
+static struct xue_dbc_reg *xue_find_dbc(struct xue *xue)
+{
+    uint32_t *xcap;
+    uint32_t next;
+    uint32_t id;
+    uint8_t *mmio = (uint8_t *)xue->xhc_mmio;
+    uint32_t *hccp1 = (uint32_t *)(mmio + 0x10);
+    const uint32_t DBC_ID = 0xA;
+
+    /**
+     * Paranoid check against a zero value. The spec mandates that
+     * at least one "supported protocol" capability must be implemented,
+     * so this should always be false.
+     */
+    if ( (*hccp1 & 0xFFFF0000) == 0 )
+        return NULL;
+
+    xcap = (uint32_t *)(mmio + (((*hccp1 & 0xFFFF0000) >> 16) << 2));
+    next = (*xcap & 0xFF00) >> 8;
+    id = *xcap & 0xFF;
+
+    /**
+     * Table 7-1 states that 'next' is relative to
+     * the current value of xcap and is a dword offset.
+     */
+    while ( id != DBC_ID && next ) {
+        xcap += next;
+        id = *xcap & 0xFF;
+        next = (*xcap & 0xFF00) >> 8;
+    }
+
+    if ( id != DBC_ID )
+        return NULL;
+
+    xue->xhc_dbc_offset = (uint64_t)xcap - (uint64_t)mmio;
+    return (struct xue_dbc_reg *)xcap;
+}
+
+/**
+ * Fields with the same interpretation for every TRB type (section 4.11.1).
+ * These are the fields defined in the TRB template, minus the ENT bit. That
+ * bit is the toggle cycle bit in link TRBs, so it shouldn't be in the
+ * template.
+ */
+static uint32_t xue_trb_cyc(const struct xue_trb *trb)
+{
+    return trb->ctrl & 0x1;
+}
+
+static uint32_t xue_trb_type(const struct xue_trb *trb)
+{
+    return (trb->ctrl & 0xFC00) >> 10;
+}
+
+static void xue_trb_set_cyc(struct xue_trb *trb, uint32_t c)
+{
+    trb->ctrl &= ~0x1UL;
+    trb->ctrl |= c;
+}
+
+static void xue_trb_set_type(struct xue_trb *trb, uint32_t t)
+{
+    trb->ctrl &= ~0xFC00UL;
+    trb->ctrl |= (t << 10);
+}
+
+/* Fields for normal TRBs */
+static void xue_trb_norm_set_buf(struct xue_trb *trb, uint64_t addr)
+{
+    trb->params = addr;
+}
+
+static void xue_trb_norm_set_len(struct xue_trb *trb, uint32_t len)
+{
+    trb->status &= ~0x1FFFFUL;
+    trb->status |= len;
+}
+
+static void xue_trb_norm_set_ioc(struct xue_trb *trb)
+{
+    trb->ctrl |= 0x20;
+}
+
+/**
+ * Fields for Transfer Event TRBs (see section 6.4.2.1). Note that event
+ * TRBs are read-only from software
+ */
+static uint64_t xue_trb_tfre_ptr(const struct xue_trb *trb)
+{
+    return trb->params;
+}
+
+static uint32_t xue_trb_tfre_cc(const struct xue_trb *trb)
+{
+    return trb->status >> 24;
+}
+
+/* Fields for link TRBs (section 6.4.4.1) */
+static void xue_trb_link_set_rsp(struct xue_trb *trb, uint64_t rsp)
+{
+    trb->params = rsp;
+}
+
+static void xue_trb_link_set_tc(struct xue_trb *trb)
+{
+    trb->ctrl |= 0x2;
+}
+
+static void xue_trb_ring_init(const struct xue *xue,
+                              struct xue_trb_ring *ring, int producer,
+                              int doorbell)
+{
+    memset(ring->trb, 0, XUE_TRB_RING_CAP * sizeof(ring->trb[0]));
+
+    ring->enq = 0;
+    ring->deq = 0;
+    ring->cyc = 1;
+    ring->db = (uint8_t)doorbell;
+
+    /*
+     * Producer implies transfer ring, so we have to place a
+     * link TRB at the end that points back to trb[0]
+     */
+    if ( producer )
+    {
+        struct xue_trb *trb = &ring->trb[XUE_TRB_RING_CAP - 1];
+        xue_trb_set_type(trb, xue_trb_link);
+        xue_trb_link_set_tc(trb);
+        xue_trb_link_set_rsp(trb, virt_to_maddr(ring->trb));
+    }
+}
+
+static int xue_trb_ring_full(const struct xue_trb_ring *ring)
+{
+    return ((ring->enq + 1) & (XUE_TRB_RING_CAP - 1)) == ring->deq;
+}
+
+static int xue_work_ring_full(const struct xue_work_ring *ring)
+{
+    return ((ring->enq + 1) & (XUE_WORK_RING_CAP - 1)) == ring->deq;
+}
+
+static uint64_t xue_work_ring_size(const struct xue_work_ring *ring)
+{
+    if ( ring->enq >= ring->deq )
+        return ring->enq - ring->deq;
+
+    return XUE_WORK_RING_CAP - ring->deq + ring->enq;
+}
+
+static void xue_push_trb(struct xue *xue, struct xue_trb_ring *ring,
+                         uint64_t dma, uint64_t len)
+{
+    struct xue_trb trb;
+
+    if ( ring->enq == XUE_TRB_RING_CAP - 1 )
+    {
+        /*
+         * We have to make sure the xHC processes the link TRB in order
+         * for wrap-around to work properly. We do this by marking the
+         * xHC as owner of the link TRB by setting the TRB's cycle bit
+         * (just like with normal TRBs).
+         */
+        struct xue_trb *link = &ring->trb[ring->enq];
+        xue_trb_set_cyc(link, ring->cyc);
+
+        ring->enq = 0;
+        ring->cyc ^= 1;
+    }
+
+    trb.params = 0;
+    trb.status = 0;
+    trb.ctrl = 0;
+
+    xue_trb_set_type(&trb, xue_trb_norm);
+    xue_trb_set_cyc(&trb, ring->cyc);
+
+    xue_trb_norm_set_buf(&trb, dma);
+    xue_trb_norm_set_len(&trb, (uint32_t)len);
+    xue_trb_norm_set_ioc(&trb);
+
+    ring->trb[ring->enq++] = trb;
+    xue_flush_range(xue, &ring->trb[ring->enq - 1], sizeof(trb));
+}
+
+static int64_t xue_push_work(struct xue *xue, struct xue_work_ring *ring,
+                             const char *buf, int64_t len)
+{
+    int64_t i = 0;
+    uint32_t start = ring->enq;
+    uint32_t end = 0;
+
+    while ( !xue_work_ring_full(ring) && i < len )
+    {
+        ring->buf[ring->enq] = buf[i++];
+        ring->enq = (ring->enq + 1) & (XUE_WORK_RING_CAP - 1);
+    }
+
+    end = ring->enq;
+
+    if ( end > start )
+        xue_flush_range(xue, &ring->buf[start], end - start);
+    else if ( i > 0 )
+    {
+        xue_flush_range(xue, &ring->buf[start], XUE_WORK_RING_CAP - start);
+        xue_flush_range(xue, &ring->buf[0], end);
+    }
+
+    return i;
+}
+
+/*
+ * Note that if IN transfer support is added, then this
+ * will need to be changed; it assumes an OUT transfer ring only
+ */
+static void xue_pop_events(struct xue *xue)
+{
+    const int trb_shift = 4;
+
+    struct xue_dbc_reg *reg = xue->dbc_reg;
+    struct xue_trb_ring *er = &xue->dbc_ering;
+    struct xue_trb_ring *tr = &xue->dbc_oring;
+    struct xue_trb *event = &er->trb[er->deq];
+    uint64_t erdp = reg->erdp;
+
+    rmb();
+
+    while ( xue_trb_cyc(event) == er->cyc ) {
+        switch (xue_trb_type(event)) {
+        case xue_trb_tfre:
+            if ( xue_trb_tfre_cc(event) != xue_trb_cc_success )
+            {
+                xue_alert("tfre error cc: %u\n", xue_trb_tfre_cc(event));
+                break;
+            }
+            tr->deq =
+                (xue_trb_tfre_ptr(event) & XUE_TRB_RING_MASK) >> trb_shift;
+            break;
+        case xue_trb_psce:
+            reg->portsc |= (XUE_PSC_ACK_MASK & reg->portsc);
+            break;
+        default:
+            break;
+        }
+
+        er->cyc = (er->deq == XUE_TRB_RING_CAP - 1) ? er->cyc ^ 1 : er->cyc;
+        er->deq = (er->deq + 1) & (XUE_TRB_RING_CAP - 1);
+        event = &er->trb[er->deq];
+    }
+
+    erdp &= ~XUE_TRB_RING_MASK;
+    erdp |= (er->deq << trb_shift);
+    wmb();
+    reg->erdp = erdp;
+}
+
+/**
+ * xue_init_ep
+ *
+ * Initializes the endpoint as specified in sections 7.6.3.2 and 7.6.9.2.
+ * Each endpoint is Bulk, so the MaxPStreams, LSA, HID, CErr, FE,
+ * Interval, Mult, and Max ESIT Payload fields are all 0.
+ *
+ * Max packet size: 1024
+ * Max burst size: debug mbs (from dbc_reg->ctrl register)
+ * EP type: 2 for OUT bulk, 6 for IN bulk
+ * TR dequeue ptr: physical base address of transfer ring
+ * Avg TRB length: software defined (see 4.14.1.1 for suggested defaults)
+ */
+static void xue_init_ep(uint32_t *ep, uint64_t mbs, uint32_t type,
+                        uint64_t ring_dma)
+{
+    memset(ep, 0, XUE_CTX_BYTES);
+
+    ep[1] = (1024 << 16) | ((uint32_t)mbs << 8) | (type << 3);
+    ep[2] = (ring_dma & 0xFFFFFFFF) | 1;
+    ep[3] = ring_dma >> 32;
+    ep[4] = 3 * 1024;
+}
+
+/* Initialize the DbC info with USB string descriptor addresses */
+static void xue_init_strings(struct xue *xue, uint32_t *info)
+{
+    uint64_t *sda;
+
+    /* clang-format off */
+    const char strings[] = {
+        6,  3, 9, 0, 4, 0,
+        8,  3, 'A', 0, 'I', 0, 'S', 0,
+        30, 3, 'X', 0, 'u', 0, 'e', 0, ' ', 0,
+               'D', 0, 'b', 0, 'C', 0, ' ', 0,
+               'D', 0, 'e', 0, 'v', 0, 'i', 0, 'c', 0, 'e', 0,
+        4, 3, '0', 0
+    };
+    /* clang-format on */
+
+    memcpy(xue->dbc_str, strings, sizeof(strings));
+
+    sda = (uint64_t *)&info[0];
+    sda[0] = virt_to_maddr(xue->dbc_str);
+    sda[1] = sda[0] + 6;
+    sda[2] = sda[0] + 6 + 8;
+    sda[3] = sda[0] + 6 + 8 + 30;
+    info[8] = (4 << 24) | (30 << 16) | (8 << 8) | 6;
+}
+
+static void xue_dump(struct xue *xue)
+{
+    struct xue_dbc_reg *r = xue->dbc_reg;
+
+    xue_debug("XUE DUMP:\n");
+    xue_debug("    ctrl: 0x%x stat: 0x%x psc: 0x%x\n", r->ctrl, r->st,
+              r->portsc);
+    xue_debug("    id: 0x%x, db: 0x%x\n", r->id, r->db);
+#if defined(__XEN__) || defined(VMM)
+    xue_debug("    erstsz: %u, erstba: 0x%lx\n", r->erstsz, r->erstba);
+    xue_debug("    erdp: 0x%lx, cp: 0x%lx\n", r->erdp, r->cp);
+#else
+    xue_debug("    erstsz: %u, erstba: 0x%llx\n", r->erstsz, r->erstba);
+    xue_debug("    erdp: 0x%llx, cp: 0x%llx\n", r->erdp, r->cp);
+#endif
+    xue_debug("    ddi1: 0x%x, ddi2: 0x%x\n", r->ddi1, r->ddi2);
+    xue_debug("    erstba == virt_to_dma(erst): %d\n",
+              r->erstba == virt_to_maddr(xue->dbc_erst));
+    xue_debug("    erdp == virt_to_dma(erst[0].base): %d\n",
+              r->erdp == xue->dbc_erst[0].base);
+    xue_debug("    cp == virt_to_dma(ctx): %d\n",
+              r->cp == virt_to_maddr(xue->dbc_ctx));
+}
+
+static void xue_enable_dbc(struct xue *xue)
+{
+    struct xue_dbc_reg *reg = xue->dbc_reg;
+
+    wmb();
+    reg->ctrl |= (1UL << XUE_CTRL_DCE);
+    wmb();
+
+    while ( (reg->ctrl & (1UL << XUE_CTRL_DCE)) == 0 )
+        xue_sys_pause();
+
+    wmb();
+    reg->portsc |= (1UL << XUE_PSC_PED);
+    wmb();
+
+    while ( (reg->ctrl & (1UL << XUE_CTRL_DCR)) == 0 )
+        xue_sys_pause();
+}
+
+static void xue_disable_dbc(struct xue *xue)
+{
+    struct xue_dbc_reg *reg = xue->dbc_reg;
+
+    reg->portsc &= ~(1UL << XUE_PSC_PED);
+    wmb();
+    reg->ctrl &= ~(1UL << XUE_CTRL_DCE);
+
+    while ( reg->ctrl & (1UL << XUE_CTRL_DCE) )
+        xue_sys_pause();
+}
+
+static int xue_init_dbc(struct xue *xue)
+{
+    uint64_t erdp = 0;
+    uint64_t out = 0;
+    uint64_t in = 0;
+    uint64_t mbs = 0;
+    struct xue_dbc_reg *reg = xue_find_dbc(xue);
+
+    if ( !reg )
+        return 0;
+
+    xue->dbc_reg = reg;
+    xue_disable_dbc(xue);
+
+    xue_trb_ring_init(xue, &xue->dbc_ering, 0, XUE_DB_INVAL);
+    xue_trb_ring_init(xue, &xue->dbc_oring, 1, XUE_DB_OUT);
+    xue_trb_ring_init(xue, &xue->dbc_iring, 1, XUE_DB_IN);
+
+    erdp = virt_to_maddr(xue->dbc_ering.trb);
+    if ( !erdp )
+        return 0;
+
+    memset(xue->dbc_erst, 0, sizeof(*xue->dbc_erst));
+    xue->dbc_erst->base = erdp;
+    xue->dbc_erst->size = XUE_TRB_RING_CAP;
+
+    mbs = (reg->ctrl & 0xFF0000) >> 16;
+    out = virt_to_maddr(xue->dbc_oring.trb);
+    in = virt_to_maddr(xue->dbc_iring.trb);
+
+    memset(xue->dbc_ctx, 0, sizeof(*xue->dbc_ctx));
+    xue_init_strings(xue, xue->dbc_ctx->info);
+    xue_init_ep(xue->dbc_ctx->ep_out, mbs, xue_ep_bulk_out, out);
+    xue_init_ep(xue->dbc_ctx->ep_in, mbs, xue_ep_bulk_in, in);
+
+    reg->erstsz = 1;
+    reg->erstba = virt_to_maddr(xue->dbc_erst);
+    reg->erdp = erdp;
+    reg->cp = virt_to_maddr(xue->dbc_ctx);
+    reg->ddi1 = (XUE_DBC_VENDOR << 16) | XUE_DBC_PROTOCOL;
+    reg->ddi2 = XUE_DBC_PRODUCT;
+
+    xue_flush_range(xue, xue->dbc_ctx, sizeof(*xue->dbc_ctx));
+    xue_flush_range(xue, xue->dbc_erst, sizeof(*xue->dbc_erst));
+    xue_flush_range(xue, xue->dbc_ering.trb, XUE_TRB_RING_BYTES);
+    xue_flush_range(xue, xue->dbc_oring.trb, XUE_TRB_RING_BYTES);
+    xue_flush_range(xue, xue->dbc_iring.trb, XUE_TRB_RING_BYTES);
+    xue_flush_range(xue, xue->dbc_owork.buf, XUE_WORK_RING_BYTES);
+
+    return 1;
+}
+
+static void xue_init_work_ring(struct xue *xue,
+                               struct xue_work_ring *wrk)
+{
+    wrk->enq = 0;
+    wrk->deq = 0;
+    wrk->dma = virt_to_maddr(wrk->buf);
+}
+
+/* @endcond */
+
+/**
+ * Initialize the DbC and enable it for transfers. First map in the DbC
+ * registers from the host controller's MMIO region. Then allocate and map
+ * DMA for the event and transfer rings. Finally, enable the DbC for
+ * the host to enumerate. On success, the DbC is ready to send packets.
+ *
+ * @param xue the xue to open (!= NULL)
+ * @param ops the xue ops to use (!= NULL)
+ * @param sys the system-specific data (may be NULL)
+ * @return 1 iff xue_open succeeded
+ */
+static int64_t xue_open(struct xue *xue)
+{
+    if ( !xue )
+        return 0;
+
+    if ( !xue_init_xhc(xue) )
+        return 0;
+
+    if ( !xue_init_dbc(xue) )
+        return 0;
+
+    xue_init_work_ring(xue, &xue->dbc_owork);
+    xue_enable_dbc(xue);
+    xue->open = 1;
+
+    return 1;
+}
+
+/**
+ * Commit the pending transfer TRBs to the DbC. This notifies
+ * the DbC of any previously-queued data on the work ring and
+ * rings the doorbell.
+ *
+ * @param xue the xue to flush
+ * @param trb the ring containing the TRBs to transfer
+ * @param wrk the work ring containing data to be flushed
+ */
+static void xue_flush(struct xue *xue, struct xue_trb_ring *trb,
+                      struct xue_work_ring *wrk)
+{
+    struct xue_dbc_reg *reg = xue->dbc_reg;
+    uint32_t db = (reg->db & 0xFFFF00FF) | (trb->db << 8);
+
+    if ( xue->open && !(reg->ctrl & (1UL << XUE_CTRL_DCE)) )
+    {
+        if ( !xue_init_dbc(xue) )
+            return;
+
+        xue_init_work_ring(xue, &xue->dbc_owork);
+        xue_enable_dbc(xue);
+    }
+
+    xue_pop_events(xue);
+
+    if ( !(reg->ctrl & (1UL << XUE_CTRL_DCR)) )
+    {
+        xue_error("DbC not configured");
+        return;
+    }
+
+    if ( reg->ctrl & (1UL << XUE_CTRL_DRC) )
+    {
+        reg->ctrl |= (1UL << XUE_CTRL_DRC);
+        reg->portsc |= (1UL << XUE_PSC_PED);
+        wmb();
+    }
+
+    if ( xue_trb_ring_full(trb) )
+        return;
+
+    if ( wrk->enq == wrk->deq )
+        return;
+    else if ( wrk->enq > wrk->deq )
+    {
+        xue_push_trb(xue, trb, wrk->dma + wrk->deq, wrk->enq - wrk->deq);
+        wrk->deq = wrk->enq;
+    }
+    else
+    {
+        xue_push_trb(xue, trb, wrk->dma + wrk->deq,
+                     XUE_WORK_RING_CAP - wrk->deq);
+        wrk->deq = 0;
+        if ( wrk->enq > 0 && !xue_trb_ring_full(trb) )
+        {
+            xue_push_trb(xue, trb, wrk->dma, wrk->enq);
+            wrk->deq = wrk->enq;
+        }
+    }
+
+    wmb();
+    reg->db = db;
+}
+
+/**
+ * Queue a single character to the DbC. A transfer TRB will be created
+ * if the character is a newline and the DbC will be notified that data is
+ * available for writing to the debug host.
+ *
+ * @param xue the xue to write to
+ * @param c the character to write
+ * @return the number of bytes written
+ */
+static int64_t xue_putc(struct xue *xue, char c)
+{
+    if ( !xue_push_work(xue, &xue->dbc_owork, &c, 1) )
+        return 0;
+
+    if ( c == '\n' )
+        xue_flush(xue, &xue->dbc_oring, &xue->dbc_owork);
+
+    return 1;
+}
+
+struct xue_uart {
+    struct xue xue;
+    struct timer timer;
+    spinlock_t *lock;
+};
+
+static struct xue_uart xue_uart;
+
+static void cf_check xue_uart_poll(void *data)
+{
+    struct serial_port *port = data;
+    struct xue_uart *uart = port->uart;
+    struct xue *xue = &uart->xue;
+    unsigned long flags = 0;
+
+    if ( spin_trylock_irqsave(&port->tx_lock, flags) )
+    {
+        xue_flush(xue, &xue->dbc_oring, &xue->dbc_owork);
+        spin_unlock_irqrestore(&port->tx_lock, flags);
+    }
+
+    serial_tx_interrupt(port, guest_cpu_user_regs());
+    set_timer(&uart->timer, NOW() + MICROSECS(XUE_POLL_INTERVAL));
+}
+
+static void __init cf_check xue_uart_init_preirq(struct serial_port *port)
+{
+    struct xue_uart *uart = port->uart;
+    uart->lock = &port->tx_lock;
+}
+
+static void __init cf_check xue_uart_init_postirq(struct serial_port *port)
+{
+    struct xue_uart *uart = port->uart;
+
+    serial_async_transmit(port);
+    init_timer(&uart->timer, xue_uart_poll, port, 0);
+    set_timer(&uart->timer, NOW() + MILLISECS(1));
+}
+
+static int cf_check xue_uart_tx_ready(struct serial_port *port)
+{
+    struct xue_uart *uart = port->uart;
+    struct xue *xue = &uart->xue;
+
+    return XUE_WORK_RING_CAP - xue_work_ring_size(&xue->dbc_owork);
+}
+
+static void cf_check xue_uart_putc(struct serial_port *port, char c)
+{
+    struct xue_uart *uart = port->uart;
+    xue_putc(&uart->xue, c);
+}
+
+static void cf_check xue_uart_flush(struct serial_port *port)
+{
+    s_time_t goal;
+    struct xue_uart *uart = port->uart;
+    struct xue *xue = &uart->xue;
+
+    xue_flush(xue, &xue->dbc_oring, &xue->dbc_owork);
+
+    goal = NOW() + MICROSECS(XUE_POLL_INTERVAL);
+    if ( uart->timer.expires > goal )
+        set_timer(&uart->timer, goal);
+}
+
+static struct uart_driver xue_uart_driver = {
+    .init_preirq = xue_uart_init_preirq,
+    .init_postirq = xue_uart_init_postirq,
+    .endboot = NULL,
+    .suspend = NULL,
+    .resume = NULL,
+    .tx_ready = xue_uart_tx_ready,
+    .putc = xue_uart_putc,
+    .flush = xue_uart_flush,
+    .getc = NULL
+};
+
+static struct xue_trb evt_trb[XUE_TRB_RING_CAP] __aligned(XUE_PAGE_SIZE);
+static struct xue_trb out_trb[XUE_TRB_RING_CAP] __aligned(XUE_PAGE_SIZE);
+static struct xue_trb in_trb[XUE_TRB_RING_CAP] __aligned(XUE_PAGE_SIZE);
+static struct xue_erst_segment erst __aligned(64);
+static struct xue_dbc_ctx ctx __aligned(64);
+static uint8_t wrk_buf[XUE_WORK_RING_CAP] __aligned(XUE_PAGE_SIZE);
+static char str_buf[XUE_PAGE_SIZE] __aligned(64);
+static char __initdata opt_dbgp[30];
+
+string_param("dbgp", opt_dbgp);
+
+void __init xue_uart_init(void)
+{
+    struct xue_uart *uart = &xue_uart;
+    struct xue *xue = &uart->xue;
+
+    if ( strncmp(opt_dbgp, "xue", 3) )
+        return;
+
+    memset(xue, 0, sizeof(*xue));
+
+    xue->dbc_ctx = &ctx;
+    xue->dbc_erst = &erst;
+    xue->dbc_ering.trb = evt_trb;
+    xue->dbc_oring.trb = out_trb;
+    xue->dbc_iring.trb = in_trb;
+    xue->dbc_owork.buf = wrk_buf;
+    xue->dbc_str = str_buf;
+
+    xue_open(xue);
+
+    serial_register_uart(SERHND_DBGP, &xue_uart_driver, &xue_uart);
+}
+
+void xue_uart_dump(void)
+{
+    struct xue_uart *uart = &xue_uart;
+    struct xue *xue = &uart->xue;
+
+    xue_dump(xue);
+}
diff --git a/xen/include/xen/serial.h b/xen/include/xen/serial.h
index 6548f0b0a9cf..803e24cda0b6 100644
--- a/xen/include/xen/serial.h
+++ b/xen/include/xen/serial.h
@@ -171,6 +171,7 @@ struct ns16550_defaults {
 };
 void ns16550_init(int index, struct ns16550_defaults *defaults);
 void ehci_dbgp_init(void);
+void xue_uart_init(void);
 
 void arm_uart_init(void);
 
-- 
git-series 0.9.1


^ permalink raw reply related	[flat|nested] 23+ messages in thread

* [PATCH v1 02/10] xue: reset XHCI ports when initializing dbc
  2022-06-07 14:30 [PATCH v1 00/10] Add Xue - console over USB 3 Debug Capability Marek Marczykowski-Górecki
  2022-06-07 14:30 ` [PATCH v1 01/10] drivers/char: Add support for Xue USB3 debugger Marek Marczykowski-Górecki
@ 2022-06-07 14:30 ` Marek Marczykowski-Górecki
  2022-06-15 14:35   ` Jan Beulich
  2022-06-07 14:30 ` [PATCH v1 03/10] xue: add support for selecting specific xhci Marek Marczykowski-Górecki
                   ` (9 subsequent siblings)
  11 siblings, 1 reply; 23+ messages in thread
From: Marek Marczykowski-Górecki @ 2022-06-07 14:30 UTC (permalink / raw)
  To: xen-devel
  Cc: Marek Marczykowski-Górecki, Andrew Cooper, George Dunlap,
	Jan Beulich, Julien Grall, Stefano Stabellini, Wei Liu

Reset ports, to force host system to re-enumerate devices. Otheriwse it
will require the cable to be re-plugged, or will wait in the
"configuring" state indefinitely.

Trick and code copied from Linux:
drivers/usb/early/xhci-dbc.c:xdbc_start()->xdbc_reset_debug_port()

Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
---
 xen/drivers/char/xue.c | 70 +++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 70 insertions(+)

diff --git a/xen/drivers/char/xue.c b/xen/drivers/char/xue.c
index e95dd09d39a8..a9ba25d9d07e 100644
--- a/xen/drivers/char/xue.c
+++ b/xen/drivers/char/xue.c
@@ -60,6 +60,10 @@
     ((1UL << XUE_PSC_CSC) | (1UL << XUE_PSC_PRC) | (1UL << XUE_PSC_PLC) |      \
      (1UL << XUE_PSC_CEC))
 
+#define     XUE_XHC_EXT_PORT_MAJOR(x)  (((x) >> 24) & 0xff)
+#define PORT_RESET  (1 << 4)
+#define PORT_CONNECT  (1 << 0)
+
 #define xue_debug(...) printk("xue debug: " __VA_ARGS__)
 #define xue_alert(...) printk("xue alert: " __VA_ARGS__)
 #define xue_error(...) printk("xue error: " __VA_ARGS__)
@@ -604,6 +608,68 @@ static void xue_init_strings(struct xue *xue, uint32_t *info)
     info[8] = (4 << 24) | (30 << 16) | (8 << 8) | 6;
 }
 
+static void xue_do_reset_debug_port(struct xue *xue, u32 id, u32 count)
+{
+    uint32_t *ops_reg;
+    uint32_t *portsc;
+    u32 val, cap_length;
+    int i;
+
+    cap_length = (*(uint32_t*)xue->xhc_mmio) & 0xff;
+    ops_reg = xue->xhc_mmio + cap_length;
+
+    id--;
+    for ( i = id; i < (id + count); i++ )
+    {
+        portsc = ops_reg + 0x100 + i * 0x4;
+        val = *portsc;
+        if ( !(val & PORT_CONNECT) )
+            *portsc = val | PORT_RESET;
+    }
+}
+
+
+static void xue_reset_debug_port(struct xue *xue)
+{
+    u32 val, port_offset, port_count;
+    uint32_t *xcap;
+    uint32_t next;
+    uint32_t id;
+    uint8_t *mmio = (uint8_t *)xue->xhc_mmio;
+    uint32_t *hccp1 = (uint32_t *)(mmio + 0x10);
+    const uint32_t PROTOCOL_ID = 0x2;
+
+    /**
+     * Paranoid check against a zero value. The spec mandates that
+     * at least one "supported protocol" capability must be implemented,
+     * so this should always be false.
+     */
+    if ( (*hccp1 & 0xFFFF0000) == 0 )
+        return;
+
+    xcap = (uint32_t *)(mmio + (((*hccp1 & 0xFFFF0000) >> 16) << 2));
+    next = (*xcap & 0xFF00) >> 8;
+    id = *xcap & 0xFF;
+
+    /* Look for "supported protocol" capability, major revision 3 */
+    for ( ; next; xcap += next, id = *xcap & 0xFF, next = (*xcap & 0xFF00) >> 8)
+    {
+        if ( id != PROTOCOL_ID && next )
+            continue;
+
+        if ( XUE_XHC_EXT_PORT_MAJOR(*xcap) != 0x3 )
+            continue;
+
+        /* extract ports offset and count from the capability structure */
+        val = *(xcap + 2);
+        port_offset = val & 0xff;
+        port_count = (val >> 8) & 0xff;
+
+        /* and reset them all */
+        xue_do_reset_debug_port(xue, port_offset, port_count);
+    }
+}
+
 static void xue_dump(struct xue *xue)
 {
     struct xue_dbc_reg *r = xue->dbc_reg;
@@ -639,6 +705,10 @@ static void xue_enable_dbc(struct xue *xue)
     while ( (reg->ctrl & (1UL << XUE_CTRL_DCE)) == 0 )
         xue_sys_pause();
 
+    /* reset ports on initial open, to force re-enumerating by the host */
+    if ( !xue->open )
+        xue_reset_debug_port(xue);
+
     wmb();
     reg->portsc |= (1UL << XUE_PSC_PED);
     wmb();
-- 
git-series 0.9.1


^ permalink raw reply related	[flat|nested] 23+ messages in thread

* [PATCH v1 03/10] xue: add support for selecting specific xhci
  2022-06-07 14:30 [PATCH v1 00/10] Add Xue - console over USB 3 Debug Capability Marek Marczykowski-Górecki
  2022-06-07 14:30 ` [PATCH v1 01/10] drivers/char: Add support for Xue USB3 debugger Marek Marczykowski-Górecki
  2022-06-07 14:30 ` [PATCH v1 02/10] xue: reset XHCI ports when initializing dbc Marek Marczykowski-Górecki
@ 2022-06-07 14:30 ` Marek Marczykowski-Górecki
  2022-06-15 14:40   ` Jan Beulich
  2022-06-07 14:30 ` [PATCH v1 04/10] ehci-dbgp: fix selecting n-th ehci controller Marek Marczykowski-Górecki
                   ` (8 subsequent siblings)
  11 siblings, 1 reply; 23+ messages in thread
From: Marek Marczykowski-Górecki @ 2022-06-07 14:30 UTC (permalink / raw)
  To: xen-devel
  Cc: Marek Marczykowski-Górecki, Andrew Cooper, George Dunlap,
	Jan Beulich, Julien Grall, Stefano Stabellini, Wei Liu

Handle parameters similar to dbgp=ehci.

Implement this by not resettting xhc_cf8 again in xue_init_xhc(), but
using a value found there if non-zero. Additionally, add xue->xhc_num to
select n-th controller.

Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
---
 docs/misc/xen-command-line.pandoc |  5 +++-
 xen/drivers/char/xue.c            | 56 ++++++++++++++++++++++++--------
 2 files changed, 47 insertions(+), 14 deletions(-)

diff --git a/docs/misc/xen-command-line.pandoc b/docs/misc/xen-command-line.pandoc
index 881fe409ac76..37a564c2386f 100644
--- a/docs/misc/xen-command-line.pandoc
+++ b/docs/misc/xen-command-line.pandoc
@@ -721,10 +721,15 @@ Available alternatives, with their meaning, are:
 
 ### dbgp
 > `= ehci[ <integer> | @pci<bus>:<slot>.<func> ]`
+> `= xue[ <integer> | @pci<bus>:<slot>.<func> ]`
 
 Specify the USB controller to use, either by instance number (when going
 over the PCI busses sequentially) or by PCI device (must be on segment 0).
 
+Use `ehci` for EHCI debug port, use `xue` for XHCI debug capability.
+Xue driver will wait indefinitely for the debug host to connect - make sure the
+cable is connected.
+
 ### debug_stack_lines
 > `= <integer>`
 
diff --git a/xen/drivers/char/xue.c b/xen/drivers/char/xue.c
index a9ba25d9d07e..b253426a95f8 100644
--- a/xen/drivers/char/xue.c
+++ b/xen/drivers/char/xue.c
@@ -204,6 +204,7 @@ struct xue {
     void *xhc_mmio;
 
     int open;
+    int xhc_num; /* look for n-th xhc */
 };
 
 static void xue_sys_pause(void)
@@ -252,24 +253,34 @@ static int xue_init_xhc(struct xue *xue)
     uint64_t bar1;
     uint64_t devfn;
 
-    /*
-     * Search PCI bus 0 for the xHC. All the host controllers supported so far
-     * are part of the chipset and are on bus 0.
-     */
-    for ( devfn = 0; devfn < 256; devfn++ ) {
-        uint32_t dev = (devfn & 0xF8) >> 3;
-        uint32_t fun = devfn & 0x07;
-        pci_sbdf_t sbdf = PCI_SBDF(0, dev, fun);
-        uint32_t hdr = pci_conf_read8(sbdf, PCI_HEADER_TYPE);
-
-        if ( hdr == 0 || hdr == 0x80 )
+    if ( xue->sbdf.sbdf == 0 )
+    {
+        /*
+         * Search PCI bus 0 for the xHC. All the host controllers supported so far
+         * are part of the chipset and are on bus 0.
+         */
+        for ( devfn = 0; devfn < 256; devfn++ )
         {
-            if ( (pci_conf_read32(sbdf, PCI_CLASS_REVISION) >> 8) == XUE_XHC_CLASSC )
+            uint32_t dev = (devfn & 0xF8) >> 3;
+            uint32_t fun = devfn & 0x07;
+            pci_sbdf_t sbdf = PCI_SBDF(0, dev, fun);
+            uint32_t hdr = pci_conf_read8(sbdf, PCI_HEADER_TYPE);
+
+            if ( hdr == 0 || hdr == 0x80 )
             {
-                xue->sbdf = sbdf;
-                break;
+                if ( (pci_conf_read32(sbdf, PCI_CLASS_REVISION) >> 8) == XUE_XHC_CLASSC )
+                {
+                    if ( xue->xhc_num-- )
+                        continue;
+                    xue->sbdf = sbdf;
+                    break;
+                }
             }
         }
+    } else {
+        /* Verify if selected device is really xHC */
+        if ( (pci_conf_read32(xue->sbdf, PCI_CLASS_REVISION) >> 8) != XUE_XHC_CLASSC )
+            xue->sbdf.sbdf = 0;
     }
 
     if ( !xue->sbdf.sbdf )
@@ -999,12 +1010,29 @@ void __init xue_uart_init(void)
 {
     struct xue_uart *uart = &xue_uart;
     struct xue *xue = &uart->xue;
+    const char *e;
 
     if ( strncmp(opt_dbgp, "xue", 3) )
         return;
 
     memset(xue, 0, sizeof(*xue));
 
+    if ( isdigit(opt_dbgp[3]) || !opt_dbgp[3] )
+    {
+        if ( opt_dbgp[3] )
+            xue->xhc_num = simple_strtoul(opt_dbgp + 3, &e, 10);
+    }
+    else if ( strncmp(opt_dbgp + 3, "@pci", 4) == 0 )
+    {
+        unsigned int bus, slot, func;
+
+        e = parse_pci(opt_dbgp + 7, NULL, &bus, &slot, &func);
+        if ( !e || *e )
+            return;
+
+        xue->sbdf = PCI_SBDF(0, bus, slot, func);
+    }
+
     xue->dbc_ctx = &ctx;
     xue->dbc_erst = &erst;
     xue->dbc_ering.trb = evt_trb;
-- 
git-series 0.9.1


^ permalink raw reply related	[flat|nested] 23+ messages in thread

* [PATCH v1 04/10] ehci-dbgp: fix selecting n-th ehci controller
  2022-06-07 14:30 [PATCH v1 00/10] Add Xue - console over USB 3 Debug Capability Marek Marczykowski-Górecki
                   ` (2 preceding siblings ...)
  2022-06-07 14:30 ` [PATCH v1 03/10] xue: add support for selecting specific xhci Marek Marczykowski-Górecki
@ 2022-06-07 14:30 ` Marek Marczykowski-Górecki
  2022-06-15 14:42   ` Jan Beulich
  2022-06-07 14:30 ` [PATCH v1 05/10] console: support multiple serial console simultaneously Marek Marczykowski-Górecki
                   ` (7 subsequent siblings)
  11 siblings, 1 reply; 23+ messages in thread
From: Marek Marczykowski-Górecki @ 2022-06-07 14:30 UTC (permalink / raw)
  To: xen-devel
  Cc: Marek Marczykowski-Górecki, Andrew Cooper, George Dunlap,
	Jan Beulich, Julien Grall, Stefano Stabellini, Wei Liu

The ehci<n> number was parsed but ignored.

Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
---
 xen/drivers/char/ehci-dbgp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/xen/drivers/char/ehci-dbgp.c b/xen/drivers/char/ehci-dbgp.c
index 16c8ff394d5c..92c588ec0aa3 100644
--- a/xen/drivers/char/ehci-dbgp.c
+++ b/xen/drivers/char/ehci-dbgp.c
@@ -1480,7 +1480,7 @@ void __init ehci_dbgp_init(void)
         unsigned int num = 0;
 
         if ( opt_dbgp[4] )
-            simple_strtoul(opt_dbgp + 4, &e, 10);
+            num = simple_strtoul(opt_dbgp + 4, &e, 10);
 
         dbgp->cap = find_dbgp(dbgp, num);
         if ( !dbgp->cap )
-- 
git-series 0.9.1


^ permalink raw reply related	[flat|nested] 23+ messages in thread

* [PATCH v1 05/10] console: support multiple serial console simultaneously
  2022-06-07 14:30 [PATCH v1 00/10] Add Xue - console over USB 3 Debug Capability Marek Marczykowski-Górecki
                   ` (3 preceding siblings ...)
  2022-06-07 14:30 ` [PATCH v1 04/10] ehci-dbgp: fix selecting n-th ehci controller Marek Marczykowski-Górecki
@ 2022-06-07 14:30 ` Marek Marczykowski-Górecki
  2022-06-07 14:30 ` [PATCH v1 06/10] IOMMU: add common API for device reserved memory Marek Marczykowski-Górecki
                   ` (6 subsequent siblings)
  11 siblings, 0 replies; 23+ messages in thread
From: Marek Marczykowski-Górecki @ 2022-06-07 14:30 UTC (permalink / raw)
  To: xen-devel
  Cc: Marek Marczykowski-Górecki, Andrew Cooper, George Dunlap,
	Jan Beulich, Julien Grall, Stefano Stabellini, Wei Liu

Previously only one serial console was supported at the same time. Using
console=com1,dbgp,vga silently ignored all but last serial console (in
this case: only dbgp and vga were active).

Fix this by storing not a single sercon_handle, but an array of them, up
to MAX_SERCONS entries. The value of MAX_SERCONS (4) is arbitrary,
inspired by the number of SERHND_IDX values.

Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
---
 xen/drivers/char/console.c | 58 ++++++++++++++++++++++++++++++---------
 1 file changed, 45 insertions(+), 13 deletions(-)

diff --git a/xen/drivers/char/console.c b/xen/drivers/char/console.c
index f9937c5134c0..44b703296487 100644
--- a/xen/drivers/char/console.c
+++ b/xen/drivers/char/console.c
@@ -113,7 +113,9 @@ static char *__read_mostly conring = _conring;
 static uint32_t __read_mostly conring_size = _CONRING_SIZE;
 static uint32_t conringc, conringp;
 
-static int __read_mostly sercon_handle = -1;
+#define MAX_SERCONS 4
+static int __read_mostly sercon_handle[MAX_SERCONS];
+static int __read_mostly nr_sercon_handle = 0;
 
 #ifdef CONFIG_X86
 /* Tristate: 0 disabled, 1 user enabled, -1 default enabled */
@@ -395,9 +397,17 @@ static unsigned int serial_rx_cons, serial_rx_prod;
 
 static void (*serial_steal_fn)(const char *, size_t nr) = early_puts;
 
+/* Redirect any console output to *fn*, if *handle* is configured as a console. */
 int console_steal(int handle, void (*fn)(const char *, size_t nr))
 {
-    if ( (handle == -1) || (handle != sercon_handle) )
+    int i;
+
+    if ( handle == -1 )
+        return 0;
+    for ( i = 0; i < nr_sercon_handle; i++ )
+        if ( handle == sercon_handle[i] )
+            break;
+    if ( nr_sercon_handle && i == nr_sercon_handle )
         return 0;
 
     if ( serial_steal_fn != NULL )
@@ -415,10 +425,13 @@ void console_giveback(int id)
 
 void console_serial_puts(const char *s, size_t nr)
 {
+    int i;
+
     if ( serial_steal_fn != NULL )
         serial_steal_fn(s, nr);
     else
-        serial_puts(sercon_handle, s, nr);
+        for ( i = 0; i < nr_sercon_handle; i++ )
+            serial_puts(sercon_handle[i], s, nr);
 
     /* Copy all serial output into PV console */
     pv_console_puts(s, nr);
@@ -956,7 +969,7 @@ void guest_printk(const struct domain *d, const char *fmt, ...)
 void __init console_init_preirq(void)
 {
     char *p;
-    int sh;
+    int sh, i;
 
     serial_init_preirq();
 
@@ -977,7 +990,8 @@ void __init console_init_preirq(void)
             continue;
         else if ( (sh = serial_parse_handle(p)) >= 0 )
         {
-            sercon_handle = sh;
+            if ( nr_sercon_handle < MAX_SERCONS )
+                sercon_handle[nr_sercon_handle++] = sh;
             serial_steal_fn = NULL;
         }
         else
@@ -996,7 +1010,8 @@ void __init console_init_preirq(void)
         opt_console_xen = 0;
 #endif
 
-    serial_set_rx_handler(sercon_handle, serial_rx);
+    for ( i = 0; i < nr_sercon_handle; i++ )
+        serial_set_rx_handler(sercon_handle[i], serial_rx);
     pv_console_set_rx_handler(serial_rx);
 
     /* HELLO WORLD --- start-of-day banner text. */
@@ -1014,7 +1029,8 @@ void __init console_init_preirq(void)
 
     if ( opt_sync_console )
     {
-        serial_start_sync(sercon_handle);
+        for ( i = 0; i < nr_sercon_handle; i++ )
+            serial_start_sync(sercon_handle[i]);
         add_taint(TAINT_SYNC_CONSOLE);
         printk("Console output is synchronous.\n");
         warning_add(warning_sync_console);
@@ -1121,13 +1137,19 @@ int __init console_has(const char *device)
 
 void console_start_log_everything(void)
 {
-    serial_start_log_everything(sercon_handle);
+    int i;
+
+    for ( i = 0; i < nr_sercon_handle; i++ )
+        serial_start_log_everything(sercon_handle[i]);
     atomic_inc(&print_everything);
 }
 
 void console_end_log_everything(void)
 {
-    serial_end_log_everything(sercon_handle);
+    int i;
+
+    for ( i = 0; i < nr_sercon_handle; i++ )
+        serial_end_log_everything(sercon_handle[i]);
     atomic_dec(&print_everything);
 }
 
@@ -1149,23 +1171,32 @@ void console_unlock_recursive_irqrestore(unsigned long flags)
 
 void console_force_unlock(void)
 {
+    int i;
+
     watchdog_disable();
     spin_debug_disable();
     spin_lock_init(&console_lock);
-    serial_force_unlock(sercon_handle);
+    for ( i = 0 ; i < nr_sercon_handle ; i++ )
+        serial_force_unlock(sercon_handle[i]);
     console_locks_busted = 1;
     console_start_sync();
 }
 
 void console_start_sync(void)
 {
+    int i;
+
     atomic_inc(&print_everything);
-    serial_start_sync(sercon_handle);
+    for ( i = 0 ; i < nr_sercon_handle ; i++ )
+        serial_start_sync(sercon_handle[i]);
 }
 
 void console_end_sync(void)
 {
-    serial_end_sync(sercon_handle);
+    int i;
+
+    for ( i = 0; i < nr_sercon_handle; i++ )
+        serial_end_sync(sercon_handle[i]);
     atomic_dec(&print_everything);
 }
 
@@ -1291,7 +1322,8 @@ static int suspend_steal_id;
 
 int console_suspend(void)
 {
-    suspend_steal_id = console_steal(sercon_handle, suspend_steal_fn);
+    if ( nr_sercon_handle )
+        suspend_steal_id = console_steal(sercon_handle[0], suspend_steal_fn);
     serial_suspend();
     return 0;
 }
-- 
git-series 0.9.1


^ permalink raw reply related	[flat|nested] 23+ messages in thread

* [PATCH v1 06/10] IOMMU: add common API for device reserved memory
  2022-06-07 14:30 [PATCH v1 00/10] Add Xue - console over USB 3 Debug Capability Marek Marczykowski-Górecki
                   ` (4 preceding siblings ...)
  2022-06-07 14:30 ` [PATCH v1 05/10] console: support multiple serial console simultaneously Marek Marczykowski-Górecki
@ 2022-06-07 14:30 ` Marek Marczykowski-Górecki
  2022-06-07 14:30 ` [PATCH v1 07/10] IOMMU/VT-d: wire common device reserved memory API Marek Marczykowski-Górecki
                   ` (5 subsequent siblings)
  11 siblings, 0 replies; 23+ messages in thread
From: Marek Marczykowski-Górecki @ 2022-06-07 14:30 UTC (permalink / raw)
  To: xen-devel
  Cc: Marek Marczykowski-Górecki, Jan Beulich, Paul Durrant,
	Roger Pau Monné

Add API similar to rmrr= and ivmd= arguments, but in a common code. This
will allow drivers to register reserved memory regardless of the IOMMU
vendor.
The direct reason for this API is xhci-dbc console driver (aka xue),
that needs to use DMA. But future change may unify command line
arguments for user-supplied reserved memory, and it may be useful for
other drivers in the future too.

This commit just introduces an API, subsequent patches will plug it in
appropriate places. The reserved memory ranges needs to be saved
locally, because at the point when they are collected, Xen doesn't know
yet which IOMMU driver will be used.

Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
---
 xen/drivers/passthrough/iommu.c | 40 ++++++++++++++++++++++++++++++++++-
 xen/include/xen/iommu.h         | 11 +++++++++-
 2 files changed, 51 insertions(+)

diff --git a/xen/drivers/passthrough/iommu.c b/xen/drivers/passthrough/iommu.c
index 9393d987c788..5c4162912359 100644
--- a/xen/drivers/passthrough/iommu.c
+++ b/xen/drivers/passthrough/iommu.c
@@ -654,6 +654,46 @@ bool_t iommu_has_feature(struct domain *d, enum iommu_feature feature)
     return is_iommu_enabled(d) && test_bit(feature, dom_iommu(d)->features);
 }
 
+#define MAX_EXTRA_RESERVED_RANGES 20
+struct extra_reserved_range {
+    xen_pfn_t start;
+    xen_ulong_t nr;
+    u32 sbdf;
+};
+static unsigned int __initdata nr_extra_reserved_ranges;
+static struct extra_reserved_range __initdata extra_reserved_ranges[MAX_EXTRA_RESERVED_RANGES];
+
+int iommu_add_extra_reserved_device_memory(xen_pfn_t start, xen_ulong_t nr, u32 sbdf)
+{
+    unsigned int idx;
+
+    if ( nr_extra_reserved_ranges >= MAX_EXTRA_RESERVED_RANGES )
+        return -ENOMEM;
+
+    idx = nr_extra_reserved_ranges++;
+    extra_reserved_ranges[idx].start = start;
+    extra_reserved_ranges[idx].nr = nr;
+    extra_reserved_ranges[idx].sbdf = sbdf;
+    return 0;
+}
+
+int iommu_get_extra_reserved_device_memory(iommu_grdm_t *func, void *ctxt)
+{
+    unsigned int idx;
+    int ret;
+
+    for ( idx = 0; idx < nr_extra_reserved_ranges; idx++ )
+    {
+        ret = func(extra_reserved_ranges[idx].start,
+                   extra_reserved_ranges[idx].nr,
+                   extra_reserved_ranges[idx].sbdf,
+                   ctxt);
+        if ( ret < 0 )
+            return ret;
+    }
+    return 0;
+}
+
 /*
  * Local variables:
  * mode: C
diff --git a/xen/include/xen/iommu.h b/xen/include/xen/iommu.h
index e0f82712ed73..97424130247c 100644
--- a/xen/include/xen/iommu.h
+++ b/xen/include/xen/iommu.h
@@ -296,6 +296,17 @@ struct iommu_ops {
 #endif
 };
 
+/*
+ * To be called by Xen internally, to register extra RMRR/IVMD ranges.
+ * Needs to be called before IOMMU initialization.
+ */
+extern int iommu_add_extra_reserved_device_memory(xen_pfn_t start, xen_ulong_t nr, u32 sbdf);
+/*
+ * To be called by specific IOMMU driver during initialization,
+ * to fetch ranges registered with iommu_add_extra_reserved_device_memory().
+ */
+extern int iommu_get_extra_reserved_device_memory(iommu_grdm_t *func, void *ctxt);
+
 #include <asm/iommu.h>
 
 #ifndef iommu_call
-- 
git-series 0.9.1


^ permalink raw reply related	[flat|nested] 23+ messages in thread

* [PATCH v1 07/10] IOMMU/VT-d: wire common device reserved memory API
  2022-06-07 14:30 [PATCH v1 00/10] Add Xue - console over USB 3 Debug Capability Marek Marczykowski-Górecki
                   ` (5 preceding siblings ...)
  2022-06-07 14:30 ` [PATCH v1 06/10] IOMMU: add common API for device reserved memory Marek Marczykowski-Górecki
@ 2022-06-07 14:30 ` Marek Marczykowski-Górecki
  2022-06-07 14:30 ` [PATCH v1 08/10] IOMMU/AMD: " Marek Marczykowski-Górecki
                   ` (4 subsequent siblings)
  11 siblings, 0 replies; 23+ messages in thread
From: Marek Marczykowski-Górecki @ 2022-06-07 14:30 UTC (permalink / raw)
  To: xen-devel; +Cc: Marek Marczykowski-Górecki, Kevin Tian

Re-use rmrr= parameter handling code to handle common device reserved
memory.

Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
---
 xen/drivers/passthrough/vtd/dmar.c | 201 +++++++++++++++++-------------
 1 file changed, 119 insertions(+), 82 deletions(-)

diff --git a/xen/drivers/passthrough/vtd/dmar.c b/xen/drivers/passthrough/vtd/dmar.c
index 367304c8739c..661a182b08d9 100644
--- a/xen/drivers/passthrough/vtd/dmar.c
+++ b/xen/drivers/passthrough/vtd/dmar.c
@@ -861,111 +861,148 @@ static struct user_rmrr __initdata user_rmrrs[MAX_USER_RMRR];
 
 /* Macro for RMRR inclusive range formatting. */
 #define ERMRRU_FMT "[%lx-%lx]"
-#define ERMRRU_ARG(eru) eru.base_pfn, eru.end_pfn
+#define ERMRRU_ARG base_pfn, end_pfn
+
+static int __init add_one_user_rmrr(unsigned long base_pfn,
+                                    unsigned long end_pfn,
+                                    unsigned int dev_count,
+                                    u32 *sbdf);
 
 static int __init add_user_rmrr(void)
 {
+    unsigned int i;
+    int ret;
+
+    for ( i = 0; i < nr_rmrr; i++ )
+    {
+        ret = add_one_user_rmrr(user_rmrrs[i].base_pfn,
+                                user_rmrrs[i].end_pfn,
+                                user_rmrrs[i].dev_count,
+                                user_rmrrs[i].sbdf);
+        if ( ret < 0 )
+            return ret;
+    }
+    return 0;
+}
+
+/* Returns 1 on success, 0 when ignoring and < 0 on error. */
+static int __init add_one_user_rmrr(unsigned long base_pfn,
+                                    unsigned long end_pfn,
+                                    unsigned int dev_count,
+                                    u32 *sbdf)
+{
     struct acpi_rmrr_unit *rmrr, *rmrru;
-    unsigned int idx, seg, i;
-    unsigned long base, end;
+    unsigned int idx, seg;
+    unsigned long base_iter;
     bool overlap;
 
-    for ( i = 0; i < nr_rmrr; i++ )
+    if ( iommu_verbose )
+        printk(XENLOG_DEBUG VTDPREFIX
+               "Adding RMRR for %d device ([0]: %#x) range "ERMRRU_FMT"\n",
+               dev_count, sbdf[0], ERMRRU_ARG);
+
+    if ( base_pfn > end_pfn )
+    {
+        printk(XENLOG_ERR VTDPREFIX
+               "Invalid RMRR Range "ERMRRU_FMT"\n",
+               ERMRRU_ARG);
+        return 0;
+    }
+
+    if ( (end_pfn - base_pfn) >= MAX_USER_RMRR_PAGES )
     {
-        base = user_rmrrs[i].base_pfn;
-        end = user_rmrrs[i].end_pfn;
+        printk(XENLOG_ERR VTDPREFIX
+               "RMRR range "ERMRRU_FMT" exceeds "\
+               __stringify(MAX_USER_RMRR_PAGES)" pages\n",
+               ERMRRU_ARG);
+        return 0;
+    }
 
-        if ( base > end )
+    overlap = false;
+    list_for_each_entry(rmrru, &acpi_rmrr_units, list)
+    {
+        if ( pfn_to_paddr(base_pfn) <= rmrru->end_address &&
+             rmrru->base_address <= pfn_to_paddr(end_pfn) )
         {
             printk(XENLOG_ERR VTDPREFIX
-                   "Invalid RMRR Range "ERMRRU_FMT"\n",
-                   ERMRRU_ARG(user_rmrrs[i]));
-            continue;
+                   "Overlapping RMRRs: "ERMRRU_FMT" and [%lx-%lx]\n",
+                   ERMRRU_ARG,
+                   paddr_to_pfn(rmrru->base_address),
+                   paddr_to_pfn(rmrru->end_address));
+            overlap = true;
+            break;
         }
+    }
+    /* Don't add overlapping RMRR. */
+    if ( overlap )
+        return 0;
 
-        if ( (end - base) >= MAX_USER_RMRR_PAGES )
+    base_iter = base_pfn;
+    do
+    {
+        if ( !mfn_valid(_mfn(base_iter)) )
         {
             printk(XENLOG_ERR VTDPREFIX
-                   "RMRR range "ERMRRU_FMT" exceeds "\
-                   __stringify(MAX_USER_RMRR_PAGES)" pages\n",
-                   ERMRRU_ARG(user_rmrrs[i]));
-            continue;
+                   "Invalid pfn in RMRR range "ERMRRU_FMT"\n",
+                   ERMRRU_ARG);
+            break;
         }
+    } while ( base_iter++ < end_pfn );
 
-        overlap = false;
-        list_for_each_entry(rmrru, &acpi_rmrr_units, list)
-        {
-            if ( pfn_to_paddr(base) <= rmrru->end_address &&
-                 rmrru->base_address <= pfn_to_paddr(end) )
-            {
-                printk(XENLOG_ERR VTDPREFIX
-                       "Overlapping RMRRs: "ERMRRU_FMT" and [%lx-%lx]\n",
-                       ERMRRU_ARG(user_rmrrs[i]),
-                       paddr_to_pfn(rmrru->base_address),
-                       paddr_to_pfn(rmrru->end_address));
-                overlap = true;
-                break;
-            }
-        }
-        /* Don't add overlapping RMRR. */
-        if ( overlap )
-            continue;
+    /* Invalid pfn in range as the loop ended before end_pfn was reached. */
+    if ( base_iter <= end_pfn )
+        return 0;
 
-        do
-        {
-            if ( !mfn_valid(_mfn(base)) )
-            {
-                printk(XENLOG_ERR VTDPREFIX
-                       "Invalid pfn in RMRR range "ERMRRU_FMT"\n",
-                       ERMRRU_ARG(user_rmrrs[i]));
-                break;
-            }
-        } while ( base++ < end );
+    rmrr = xzalloc(struct acpi_rmrr_unit);
+    if ( !rmrr )
+        return -ENOMEM;
 
-        /* Invalid pfn in range as the loop ended before end_pfn was reached. */
-        if ( base <= end )
-            continue;
+    rmrr->scope.devices = xmalloc_array(u16, dev_count);
+    if ( !rmrr->scope.devices )
+    {
+        xfree(rmrr);
+        return -ENOMEM;
+    }
 
-        rmrr = xzalloc(struct acpi_rmrr_unit);
-        if ( !rmrr )
-            return -ENOMEM;
+    seg = 0;
+    for ( idx = 0; idx < dev_count; idx++ )
+    {
+        rmrr->scope.devices[idx] = sbdf[idx];
+        seg |= PCI_SEG(sbdf[idx]);
+    }
+    if ( seg != PCI_SEG(sbdf[0]) )
+    {
+        printk(XENLOG_ERR VTDPREFIX
+               "Segments are not equal for RMRR range "ERMRRU_FMT"\n",
+               ERMRRU_ARG);
+        scope_devices_free(&rmrr->scope);
+        xfree(rmrr);
+        return 0;
+    }
 
-        rmrr->scope.devices = xmalloc_array(u16, user_rmrrs[i].dev_count);
-        if ( !rmrr->scope.devices )
-        {
-            xfree(rmrr);
-            return -ENOMEM;
-        }
+    rmrr->segment = seg;
+    rmrr->base_address = pfn_to_paddr(base_pfn);
+    /* Align the end_address to the end of the page */
+    rmrr->end_address = pfn_to_paddr(end_pfn) | ~PAGE_MASK;
+    rmrr->scope.devices_cnt = dev_count;
 
-        seg = 0;
-        for ( idx = 0; idx < user_rmrrs[i].dev_count; idx++ )
-        {
-            rmrr->scope.devices[idx] = user_rmrrs[i].sbdf[idx];
-            seg |= PCI_SEG(user_rmrrs[i].sbdf[idx]);
-        }
-        if ( seg != PCI_SEG(user_rmrrs[i].sbdf[0]) )
-        {
-            printk(XENLOG_ERR VTDPREFIX
-                   "Segments are not equal for RMRR range "ERMRRU_FMT"\n",
-                   ERMRRU_ARG(user_rmrrs[i]));
-            scope_devices_free(&rmrr->scope);
-            xfree(rmrr);
-            continue;
-        }
+    if ( register_one_rmrr(rmrr) )
+        printk(XENLOG_ERR VTDPREFIX
+               "Could not register RMMR range "ERMRRU_FMT"\n",
+               ERMRRU_ARG);
 
-        rmrr->segment = seg;
-        rmrr->base_address = pfn_to_paddr(user_rmrrs[i].base_pfn);
-        /* Align the end_address to the end of the page */
-        rmrr->end_address = pfn_to_paddr(user_rmrrs[i].end_pfn) | ~PAGE_MASK;
-        rmrr->scope.devices_cnt = user_rmrrs[i].dev_count;
+    return 1;
+}
 
-        if ( register_one_rmrr(rmrr) )
-            printk(XENLOG_ERR VTDPREFIX
-                   "Could not register RMMR range "ERMRRU_FMT"\n",
-                   ERMRRU_ARG(user_rmrrs[i]));
-    }
+static int __init cf_check add_one_extra_rmrr(xen_pfn_t start, xen_ulong_t nr, u32 id, void *ctxt)
+{
+    u32 sbdf_array[] = { id };
+    return add_one_user_rmrr(start, start+nr, 1, sbdf_array);
+}
 
-    return 0;
+static int __init add_extra_rmrr(void)
+{
+    return iommu_get_extra_reserved_device_memory(add_one_extra_rmrr, NULL);
 }
 
 #include <asm/tboot.h>
@@ -1010,7 +1047,7 @@ int __init acpi_dmar_init(void)
     {
         iommu_init_ops = &intel_iommu_init_ops;
 
-        return add_user_rmrr();
+        return add_user_rmrr() || add_extra_rmrr();
     }
 
     return ret;
-- 
git-series 0.9.1


^ permalink raw reply related	[flat|nested] 23+ messages in thread

* [PATCH v1 08/10] IOMMU/AMD: wire common device reserved memory API
  2022-06-07 14:30 [PATCH v1 00/10] Add Xue - console over USB 3 Debug Capability Marek Marczykowski-Górecki
                   ` (6 preceding siblings ...)
  2022-06-07 14:30 ` [PATCH v1 07/10] IOMMU/VT-d: wire common device reserved memory API Marek Marczykowski-Górecki
@ 2022-06-07 14:30 ` Marek Marczykowski-Górecki
  2022-06-07 14:30 ` [PATCH v1 09/10] xue: mark DMA buffers as reserved for the device Marek Marczykowski-Górecki
                   ` (3 subsequent siblings)
  11 siblings, 0 replies; 23+ messages in thread
From: Marek Marczykowski-Górecki @ 2022-06-07 14:30 UTC (permalink / raw)
  To: xen-devel; +Cc: Marek Marczykowski-Górecki, Jan Beulich, Andrew Cooper

Register common device reserved memory similar to how ivmd= parameter is
handled.

Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
---
 xen/drivers/passthrough/amd/iommu_acpi.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/xen/drivers/passthrough/amd/iommu_acpi.c b/xen/drivers/passthrough/amd/iommu_acpi.c
index ac6835225bae..2a4896c05442 100644
--- a/xen/drivers/passthrough/amd/iommu_acpi.c
+++ b/xen/drivers/passthrough/amd/iommu_acpi.c
@@ -1078,6 +1078,20 @@ static inline bool_t is_ivmd_block(u8 type)
             type == ACPI_IVRS_TYPE_MEMORY_IOMMU);
 }
 
+static int __init cf_check add_one_extra_ivmd(xen_pfn_t start, xen_ulong_t nr, u32 id, void *ctxt)
+{
+    struct acpi_ivrs_memory ivmd;
+
+    ivmd.start_address = start << PAGE_SHIFT;
+    ivmd.memory_length = nr << PAGE_SHIFT;
+    ivmd.header.flags = ACPI_IVMD_UNITY |
+                        ACPI_IVMD_READ | ACPI_IVMD_WRITE;
+    ivmd.header.length = sizeof(ivmd);
+    ivmd.header.device_id = id;
+    ivmd.header.type = ACPI_IVRS_TYPE_MEMORY_ONE;
+    return parse_ivmd_block(&ivmd);
+}
+
 static int __init cf_check parse_ivrs_table(struct acpi_table_header *table)
 {
     const struct acpi_ivrs_header *ivrs_block;
@@ -1121,6 +1135,8 @@ static int __init cf_check parse_ivrs_table(struct acpi_table_header *table)
         AMD_IOMMU_DEBUG("IVMD: %u command line provided entries\n", nr_ivmd);
     for ( i = 0; !error && i < nr_ivmd; ++i )
         error = parse_ivmd_block(user_ivmds + i);
+    if ( !error )
+        error = iommu_get_extra_reserved_device_memory(add_one_extra_ivmd, NULL);
 
     /* Each IO-APIC must have been mentioned in the table. */
     for ( apic = 0; !error && iommu_intremap && apic < nr_ioapics; ++apic )
-- 
git-series 0.9.1


^ permalink raw reply related	[flat|nested] 23+ messages in thread

* [PATCH v1 09/10] xue: mark DMA buffers as reserved for the device
  2022-06-07 14:30 [PATCH v1 00/10] Add Xue - console over USB 3 Debug Capability Marek Marczykowski-Górecki
                   ` (7 preceding siblings ...)
  2022-06-07 14:30 ` [PATCH v1 08/10] IOMMU/AMD: " Marek Marczykowski-Górecki
@ 2022-06-07 14:30 ` Marek Marczykowski-Górecki
  2022-06-07 14:30 ` [PATCH v1 10/10] xue: allow driving the rest of XHCI by a domain while Xen uses DbC Marek Marczykowski-Górecki
                   ` (2 subsequent siblings)
  11 siblings, 0 replies; 23+ messages in thread
From: Marek Marczykowski-Górecki @ 2022-06-07 14:30 UTC (permalink / raw)
  To: xen-devel
  Cc: Marek Marczykowski-Górecki, Andrew Cooper, George Dunlap,
	Jan Beulich, Julien Grall, Stefano Stabellini, Wei Liu,
	Kevin Tian

The important part is to include those buffers in IOMMU page table
relevant for the USB controller. Otherwise, DbC will stop working as
soon as IOMMU is enabled, regardless of to which domain device assigned
(be it xen or dom0).
If the device is passed through to dom0 or other domain (see later
patches), that domain will effectively have access to those buffers too.
It does give such domain yet another way to DoS the system (as is the
case when having PCI device assigned already), but also possibly steal
the console ring content. Thus, such domain should be a trusted one.
In any case, prevent anything else being placed on those pages by adding
artificial padding.

Using this API for DbC pages requires raising MAX_USER_RMRR_PAGES.

Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
---
 xen/drivers/char/xue.c             | 45 ++++++++++++++++++++-----------
 xen/drivers/passthrough/vtd/dmar.c |  2 +-
 2 files changed, 31 insertions(+), 16 deletions(-)

diff --git a/xen/drivers/char/xue.c b/xen/drivers/char/xue.c
index b253426a95f8..6fd26c3d38a8 100644
--- a/xen/drivers/char/xue.c
+++ b/xen/drivers/char/xue.c
@@ -26,6 +26,7 @@
 #include <xen/serial.h>
 #include <xen/timer.h>
 #include <xen/param.h>
+#include <xen/iommu.h>
 #include <asm/fixmap.h>
 #include <asm/io.h>
 #include <xen/mm.h>
@@ -995,13 +996,21 @@ static struct uart_driver xue_uart_driver = {
     .getc = NULL
 };
 
-static struct xue_trb evt_trb[XUE_TRB_RING_CAP] __aligned(XUE_PAGE_SIZE);
-static struct xue_trb out_trb[XUE_TRB_RING_CAP] __aligned(XUE_PAGE_SIZE);
-static struct xue_trb in_trb[XUE_TRB_RING_CAP] __aligned(XUE_PAGE_SIZE);
-static struct xue_erst_segment erst __aligned(64);
-static struct xue_dbc_ctx ctx __aligned(64);
-static uint8_t wrk_buf[XUE_WORK_RING_CAP] __aligned(XUE_PAGE_SIZE);
-static char str_buf[XUE_PAGE_SIZE] __aligned(64);
+struct xue_dma_bufs {
+    struct xue_trb evt_trb[XUE_TRB_RING_CAP] __aligned(XUE_PAGE_SIZE);
+    struct xue_trb out_trb[XUE_TRB_RING_CAP] __aligned(XUE_PAGE_SIZE);
+    struct xue_trb in_trb[XUE_TRB_RING_CAP] __aligned(XUE_PAGE_SIZE);
+    struct xue_erst_segment erst __aligned(64);
+    struct xue_dbc_ctx ctx __aligned(64);
+    uint8_t wrk_buf[XUE_WORK_RING_CAP] __aligned(XUE_PAGE_SIZE);
+    char str_buf[XUE_PAGE_SIZE] __aligned(64);
+    /*
+     * Don't place anything else on this page - it will be
+     * DMA-reachable by the USB controller.
+     */
+    char _pad[0] __aligned(XUE_PAGE_SIZE);
+};
+static struct xue_dma_bufs xue_dma_bufs __aligned(XUE_PAGE_SIZE);
 static char __initdata opt_dbgp[30];
 
 string_param("dbgp", opt_dbgp);
@@ -1033,15 +1042,21 @@ void __init xue_uart_init(void)
         xue->sbdf = PCI_SBDF(0, bus, slot, func);
     }
 
-    xue->dbc_ctx = &ctx;
-    xue->dbc_erst = &erst;
-    xue->dbc_ering.trb = evt_trb;
-    xue->dbc_oring.trb = out_trb;
-    xue->dbc_iring.trb = in_trb;
-    xue->dbc_owork.buf = wrk_buf;
-    xue->dbc_str = str_buf;
+    xue->dbc_ctx = &xue_dma_bufs.ctx;
+    xue->dbc_erst = &xue_dma_bufs.erst;
+    xue->dbc_ering.trb = xue_dma_bufs.evt_trb;
+    xue->dbc_oring.trb = xue_dma_bufs.out_trb;
+    xue->dbc_iring.trb = xue_dma_bufs.in_trb;
+    xue->dbc_owork.buf = xue_dma_bufs.wrk_buf;
+    xue->dbc_str = xue_dma_bufs.str_buf;
 
-    xue_open(xue);
+    if ( xue_open(xue) )
+    {
+        iommu_add_extra_reserved_device_memory(
+                PFN_DOWN(virt_to_maddr(&xue_dma_bufs)),
+                PFN_UP(sizeof(xue_dma_bufs)),
+                uart->xue.sbdf.sbdf);
+    }
 
     serial_register_uart(SERHND_DBGP, &xue_uart_driver, &xue_uart);
 }
diff --git a/xen/drivers/passthrough/vtd/dmar.c b/xen/drivers/passthrough/vtd/dmar.c
index 661a182b08d9..2caa3e9ad1b0 100644
--- a/xen/drivers/passthrough/vtd/dmar.c
+++ b/xen/drivers/passthrough/vtd/dmar.c
@@ -845,7 +845,7 @@ out:
     return ret;
 }
 
-#define MAX_USER_RMRR_PAGES 16
+#define MAX_USER_RMRR_PAGES 64
 #define MAX_USER_RMRR 10
 
 /* RMRR units derived from command line rmrr option. */
-- 
git-series 0.9.1


^ permalink raw reply related	[flat|nested] 23+ messages in thread

* [PATCH v1 10/10] xue: allow driving the rest of XHCI by a domain while Xen uses DbC
  2022-06-07 14:30 [PATCH v1 00/10] Add Xue - console over USB 3 Debug Capability Marek Marczykowski-Górecki
                   ` (8 preceding siblings ...)
  2022-06-07 14:30 ` [PATCH v1 09/10] xue: mark DMA buffers as reserved for the device Marek Marczykowski-Górecki
@ 2022-06-07 14:30 ` Marek Marczykowski-Górecki
  2022-06-07 18:48 ` [PATCH v1 00/10] Add Xue - console over USB 3 Debug Capability Tamas K Lengyel
  2022-07-06  7:30 ` Henry Wang
  11 siblings, 0 replies; 23+ messages in thread
From: Marek Marczykowski-Górecki @ 2022-06-07 14:30 UTC (permalink / raw)
  To: xen-devel
  Cc: Marek Marczykowski-Górecki, Andrew Cooper, George Dunlap,
	Jan Beulich, Julien Grall, Stefano Stabellini, Wei Liu

That's possible, because the capability was designed specifically to
allow separate driver handle it, in parallel to unmodified xhci driver
(separate set of registers, pretending the port is "disconnected" for
the main xhci driver etc). It works with Linux dom0, although requires
an awful hack - re-enabling bus mastering behind dom0's backs.
Linux driver does similar thing - see
drivers/usb/early/xhci-dbc.c:xdbc_handle_events().

To avoid Linux messing with the DbC, mark this MMIO area as read-only.

Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
---
 xen/drivers/char/xue.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/xen/drivers/char/xue.c b/xen/drivers/char/xue.c
index 6fd26c3d38a8..85aed0bccbbf 100644
--- a/xen/drivers/char/xue.c
+++ b/xen/drivers/char/xue.c
@@ -27,6 +27,7 @@
 #include <xen/timer.h>
 #include <xen/param.h>
 #include <xen/iommu.h>
+#include <xen/rangeset.h>
 #include <asm/fixmap.h>
 #include <asm/io.h>
 #include <xen/mm.h>
@@ -846,6 +847,7 @@ static void xue_flush(struct xue *xue, struct xue_trb_ring *trb,
 {
     struct xue_dbc_reg *reg = xue->dbc_reg;
     uint32_t db = (reg->db & 0xFFFF00FF) | (trb->db << 8);
+    uint32_t cmd;
 
     if ( xue->open && !(reg->ctrl & (1UL << XUE_CTRL_DCE)) )
     {
@@ -856,6 +858,16 @@ static void xue_flush(struct xue *xue, struct xue_trb_ring *trb,
         xue_enable_dbc(xue);
     }
 
+    /* Re-enable bus mastering, if dom0 (or other) disabled it in the meantime. */
+    cmd = pci_conf_read16(xue->sbdf, PCI_COMMAND);
+#define XUE_XHCI_CMD_REQUIRED (PCI_COMMAND_MEMORY|PCI_COMMAND_MASTER)
+    if ( (cmd & XUE_XHCI_CMD_REQUIRED) != XUE_XHCI_CMD_REQUIRED )
+    {
+        cmd |= XUE_XHCI_CMD_REQUIRED;
+        pci_conf_write16(xue->sbdf, PCI_COMMAND, cmd);
+    }
+#undef XUE_XHCI_CMD_REQUIRED
+
     xue_pop_events(xue);
 
     if ( !(reg->ctrl & (1UL << XUE_CTRL_DCR)) )
@@ -955,6 +967,13 @@ static void __init cf_check xue_uart_init_postirq(struct serial_port *port)
     serial_async_transmit(port);
     init_timer(&uart->timer, xue_uart_poll, port, 0);
     set_timer(&uart->timer, NOW() + MILLISECS(1));
+
+#ifdef CONFIG_X86
+    if ( rangeset_add_range(mmio_ro_ranges,
+                PFN_DOWN(uart->xue.xhc_mmio_phys + uart->xue.xhc_dbc_offset),
+                PFN_UP(uart->xue.xhc_mmio_phys + uart->xue.xhc_dbc_offset + sizeof(*uart->xue.dbc_reg)) - 1) )
+        printk(XENLOG_INFO "Error while adding MMIO range of device to mmio_ro_ranges\n");
+#endif
 }
 
 static int cf_check xue_uart_tx_ready(struct serial_port *port)
-- 
git-series 0.9.1


^ permalink raw reply related	[flat|nested] 23+ messages in thread

* Re: [PATCH v1 00/10] Add Xue - console over USB 3 Debug Capability
  2022-06-07 14:30 [PATCH v1 00/10] Add Xue - console over USB 3 Debug Capability Marek Marczykowski-Górecki
                   ` (9 preceding siblings ...)
  2022-06-07 14:30 ` [PATCH v1 10/10] xue: allow driving the rest of XHCI by a domain while Xen uses DbC Marek Marczykowski-Górecki
@ 2022-06-07 18:48 ` Tamas K Lengyel
  2022-07-06  7:30 ` Henry Wang
  11 siblings, 0 replies; 23+ messages in thread
From: Tamas K Lengyel @ 2022-06-07 18:48 UTC (permalink / raw)
  To: Marek Marczykowski-Górecki
  Cc: xen-devel, Andrew Cooper, George Dunlap, Jan Beulich,
	Julien Grall, Stefano Stabellini, Wei Liu, Roger Pau Monné,
	Paul Durrant, Kevin Tian, Connor Davis

On Tue, Jun 7, 2022 at 10:31 AM Marek Marczykowski-Górecki
<marmarek@invisiblethingslab.com> wrote:
>
> This is integration of https://github.com/connojd/xue into mainline Xen.
> This patch series includes several patches that I made in the process, some are
> very loosely related.
>
> The driver developed by Connor supports output-only console via USB3 debug
> capability. The capability is designed to operate mostly independently of
> normal XHCI driver, so this patch series allows dom0 to drive standard USB3
> controller part, while Xen uses DbC for console output.
>
> Changes since RFC:
>  - move the driver to xue.c, remove non-Xen parts, remove now unneeded abstraction
>  - adjust for Xen code style
>  - build for x86 only
>  - drop patch hidding the device from dom0

Tested-by: Tamas K Lengyel <tamas@tklengyel.com>


^ permalink raw reply	[flat|nested] 23+ messages in thread

* Re: [PATCH v1 01/10] drivers/char: Add support for Xue USB3 debugger
  2022-06-07 14:30 ` [PATCH v1 01/10] drivers/char: Add support for Xue USB3 debugger Marek Marczykowski-Górecki
@ 2022-06-15 14:25   ` Jan Beulich
  2022-06-22 15:47     ` Marek Marczykowski-Górecki
  0 siblings, 1 reply; 23+ messages in thread
From: Jan Beulich @ 2022-06-15 14:25 UTC (permalink / raw)
  To: Marek Marczykowski-Górecki
  Cc: Connor Davis, Andrew Cooper, Roger Pau Monné,
	Wei Liu, George Dunlap, Julien Grall, Stefano Stabellini,
	xen-devel

On 07.06.2022 16:30, Marek Marczykowski-Górecki wrote:
> From: Connor Davis <davisc@ainfosec.com>
> 
> [Connor]
> Xue is a cross-platform USB 3 debugger that drives the Debug
> Capability (DbC) of xHCI-compliant host controllers. This patch
> implements the operations needed for xue to initialize the host
> controller's DbC and communicate with it. It also implements a struct
> uart_driver that uses xue as a backend. Note that only target -> host
> communication is supported for now. To use Xue as a console, add
> 'console=dbgp dbgp=xue' to the command line.

Which suggests that the command line doc also wants updating here.

> --- a/xen/drivers/char/Kconfig
> +++ b/xen/drivers/char/Kconfig
> @@ -74,3 +74,10 @@ config HAS_EHCI
>  	help
>  	  This selects the USB based EHCI debug port to be used as a UART. If
>  	  you have an x86 based system with USB, say Y.
> +
> +config HAS_XHCI
> +	bool
> +	depends on X86

This isn't very useful when there's no prompt, and only "select" would
enable an option. Even if HAS_EHCI has it (for whatever reason), I'd
prefer if we could avoid proliferation of the oddity.

> +	help
> +      This selects the USB based XHCI debug capability to be used as a UART. If
> +      you have an x86 based system with USB3, say Y.

Indentation looks wrong here - the HAS_EHCI one in context shows how
it's expected to be.

> --- /dev/null
> +++ b/xen/drivers/char/xue.c
> @@ -0,0 +1,957 @@
> +/*
> + * drivers/char/xue.c
> + *
> + * Xen port for the xue debugger

Since even here it's not spelled out - may I ask what "xue" actually
stands for (assumng it's an acronym)?

> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; If not, see <http://www.gnu.org/licenses/>.
> + *
> + * Copyright (c) 2019 Assured Information Security.
> + */
> +
> +#include <xen/delay.h>
> +#include <xen/types.h>
> +#include <asm/string.h>
> +#include <asm/system.h>
> +#include <xen/serial.h>
> +#include <xen/timer.h>
> +#include <xen/param.h>
> +#include <asm/fixmap.h>
> +#include <asm/io.h>
> +#include <xen/mm.h>
> +
> +#define XUE_POLL_INTERVAL 100 /* us */
> +
> +#define XUE_PAGE_SIZE 4096ULL
> +
> +/* Supported xHC PCI configurations */
> +#define XUE_XHC_CLASSC 0xC0330ULL

While I'm not meaning to fully review the code in this file (for lack
of knowledge on xhci), the two ULL suffixes above strike me as odd.
Is there a specific reason these can't just be U?

> +/* DbC idVendor and idProduct */
> +#define XUE_DBC_VENDOR 0x1D6B
> +#define XUE_DBC_PRODUCT 0x0010
> +#define XUE_DBC_PROTOCOL 0x0000
> +
> +/* DCCTRL fields */
> +#define XUE_CTRL_DCR 0
> +#define XUE_CTRL_HOT 2
> +#define XUE_CTRL_HIT 3
> +#define XUE_CTRL_DRC 4
> +#define XUE_CTRL_DCE 31
> +
> +/* DCPORTSC fields */
> +#define XUE_PSC_PED 1
> +#define XUE_PSC_CSC 17
> +#define XUE_PSC_PRC 21
> +#define XUE_PSC_PLC 22
> +#define XUE_PSC_CEC 23
> +
> +#define XUE_PSC_ACK_MASK                                                       \
> +    ((1UL << XUE_PSC_CSC) | (1UL << XUE_PSC_PRC) | (1UL << XUE_PSC_PLC) |      \
> +     (1UL << XUE_PSC_CEC))
> +
> +#define xue_debug(...) printk("xue debug: " __VA_ARGS__)
> +#define xue_alert(...) printk("xue alert: " __VA_ARGS__)
> +#define xue_error(...) printk("xue error: " __VA_ARGS__)
> +
> +/******************************************************************************
> + * TRB ring (summarized from the manual):
> + *
> + * TRB rings are circular queues of TRBs shared between the xHC and the driver.
> + * Each ring has one producer and one consumer. The DbC has one event
> + * ring and two transfer rings; one IN and one OUT.
> + *
> + * The DbC hardware is the producer on the event ring, and
> + * xue is the consumer. This means that event TRBs are read-only from
> + * the xue.
> + *
> + * OTOH, xue is the producer of transfer TRBs on the two transfer
> + * rings, so xue enqueues transfers, and the hardware dequeues
> + * them. The dequeue pointer of a transfer ring is read by
> + * xue by examining the latest transfer event TRB on the event ring. The
> + * transfer event TRB contains the address of the transfer TRB that generated
> + * the event.
> + *
> + * To make each transfer ring circular, the last TRB must be a link TRB, which
> + * points to the beginning of the next queue. Note that this implementation
> + * does not support multiple segments, so each link TRB points back to the
> + * beginning of its own segment.
> + ******************************************************************************/
> +
> +/* TRB types */
> +enum {
> +    xue_trb_norm = 1,
> +    xue_trb_link = 6,
> +    xue_trb_tfre = 32,
> +    xue_trb_psce = 34
> +};
> +
> +/* TRB completion codes */
> +enum { xue_trb_cc_success = 1, xue_trb_cc_trb_err = 5 };
> +
> +/* DbC endpoint types */
> +enum { xue_ep_bulk_out = 2, xue_ep_bulk_in = 6 };
> +
> +/* DMA/MMIO structures */
> +#pragma pack(push, 1)

Why? There's no mis-aligned field ...

> +struct xue_trb {
> +    uint64_t params;
> +    uint32_t status;
> +    uint32_t ctrl;
> +};
> +
> +struct xue_erst_segment {
> +    uint64_t base;
> +    uint16_t size;
> +    uint8_t rsvdz[6];
> +};
> +
> +#define XUE_CTX_SIZE 16
> +#define XUE_CTX_BYTES (XUE_CTX_SIZE * 4)
> +
> +struct xue_dbc_ctx {
> +    uint32_t info[XUE_CTX_SIZE];
> +    uint32_t ep_out[XUE_CTX_SIZE];
> +    uint32_t ep_in[XUE_CTX_SIZE];
> +};
> +
> +struct xue_dbc_reg {
> +    uint32_t id;
> +    uint32_t db;
> +    uint32_t erstsz;
> +    uint32_t rsvdz;
> +    uint64_t erstba;
> +    uint64_t erdp;
> +    uint32_t ctrl;
> +    uint32_t st;
> +    uint32_t portsc;
> +    uint32_t rsvdp;
> +    uint64_t cp;
> +    uint32_t ddi1;
> +    uint32_t ddi2;
> +};
> +#pragma pack(pop)

... anywhere in these structures, afaict.

> +static void xue_sys_pause(void)
> +{
> +    __asm volatile("pause" ::: "memory");

Nit: In Xen we don't normally use __asm, but asm.

> +static void xue_flush_range(struct xue *xue, void *ptr, uint32_t bytes)
> +{
> +    uint32_t i;
> +
> +    const uint32_t clshft = 6;
> +    const uint32_t clsize = (1UL << clshft);
> +    const uint32_t clmask = clsize - 1;
> +
> +    uint32_t lines = (bytes >> clshft);
> +    lines += (bytes & clmask) != 0;
> +
> +    for ( i = 0; i < lines; i++ )
> +        clflush((void *)((uint64_t)ptr + (i * clsize)));
> +}

Please drop this function (which doesn't even use its first parameter)
and use cache_flush() instead. (At the example of this though, please
see ./CODING_STYLE for the use of fixed-width types. I understand
there are many places where their use is appropriate in a drivers, but
none of the uses above look to fall in this class.)

> +static int xue_init_xhc(struct xue *xue)

Looks like this function returns boolean, and hence wants to have bool
return type. Also looks like this can be __init. Both remarks similarly
apply to xue_open() (the only caller of this function).

> +{
> +    uint32_t bar0;
> +    uint64_t bar1;
> +    uint64_t devfn;
> +
> +    /*
> +     * Search PCI bus 0 for the xHC. All the host controllers supported so far
> +     * are part of the chipset and are on bus 0.
> +     */
> +    for ( devfn = 0; devfn < 256; devfn++ ) {

Nit: Xen style wants the brace on its own line, like you have almost
everywhere else.

> +        uint32_t dev = (devfn & 0xF8) >> 3;
> +        uint32_t fun = devfn & 0x07;
> +        pci_sbdf_t sbdf = PCI_SBDF(0, dev, fun);

This is at best an abuse, as per

#define PCI_SBDF(s, b, d...) PCI_(SBDF, count_args(s, b, ##d))(s, b, ##d)

But really I think this generates the wrong coordinates. What you can
fold is devfn, i.e. PCI_SBDF(0, 0, devfn). (If you don't want to use
that form, then please avoid open-coding PCI_SLOT() and PCI_FUNC().)

> +        uint32_t hdr = pci_conf_read8(sbdf, PCI_HEADER_TYPE);
> +
> +        if ( hdr == 0 || hdr == 0x80 )
> +        {
> +            if ( (pci_conf_read32(sbdf, PCI_CLASS_REVISION) >> 8) == XUE_XHC_CLASSC )
> +            {
> +                xue->sbdf = sbdf;
> +                break;
> +            }
> +        }
> +    }
> +
> +    if ( !xue->sbdf.sbdf )
> +    {
> +        xue_error("Compatible xHC not found on bus 0\n");
> +        return 0;
> +    }
> +
> +    /* ...we found it, so parse the BAR and map the registers */
> +    bar0 = pci_conf_read32(xue->sbdf, PCI_BASE_ADDRESS_0);
> +    bar1 = pci_conf_read32(xue->sbdf, PCI_BASE_ADDRESS_1);

What if there are multiple?

> +    /* IO BARs not allowed; BAR must be 64-bit */
> +    if ( (bar0 & 0x1) != 0 || ((bar0 & 0x6) >> 1) != 2 )

Please don't open-code constants from xen/pci.h.

> +        return 0;
> +
> +    pci_conf_write32(xue->sbdf, PCI_BASE_ADDRESS_0, 0xFFFFFFFF);
> +    xue->xhc_mmio_size = ~(pci_conf_read32(xue->sbdf, PCI_BASE_ADDRESS_0) & 0xFFFFFFF0) + 1;

Same here and ...

> +    pci_conf_write32(xue->sbdf, PCI_BASE_ADDRESS_0, bar0);
> +
> +    xue->xhc_mmio_phys = (bar0 & 0xFFFFFFF0) | (bar1 << 32);

... here.

> +static struct uart_driver xue_uart_driver = {
> +    .init_preirq = xue_uart_init_preirq,
> +    .init_postirq = xue_uart_init_postirq,
> +    .endboot = NULL,
> +    .suspend = NULL,
> +    .resume = NULL,
> +    .tx_ready = xue_uart_tx_ready,
> +    .putc = xue_uart_putc,
> +    .flush = xue_uart_flush,
> +    .getc = NULL
> +};

Please omit the NULL initializers.

> +static struct xue_trb evt_trb[XUE_TRB_RING_CAP] __aligned(XUE_PAGE_SIZE);
> +static struct xue_trb out_trb[XUE_TRB_RING_CAP] __aligned(XUE_PAGE_SIZE);
> +static struct xue_trb in_trb[XUE_TRB_RING_CAP] __aligned(XUE_PAGE_SIZE);
> +static struct xue_erst_segment erst __aligned(64);
> +static struct xue_dbc_ctx ctx __aligned(64);
> +static uint8_t wrk_buf[XUE_WORK_RING_CAP] __aligned(XUE_PAGE_SIZE);
> +static char str_buf[XUE_PAGE_SIZE] __aligned(64);
> +static char __initdata opt_dbgp[30];
> +
> +string_param("dbgp", opt_dbgp);
> +
> +void __init xue_uart_init(void)
> +{
> +    struct xue_uart *uart = &xue_uart;
> +    struct xue *xue = &uart->xue;
> +
> +    if ( strncmp(opt_dbgp, "xue", 3) )
> +        return;
> +
> +    memset(xue, 0, sizeof(*xue));
> +
> +    xue->dbc_ctx = &ctx;
> +    xue->dbc_erst = &erst;
> +    xue->dbc_ering.trb = evt_trb;
> +    xue->dbc_oring.trb = out_trb;
> +    xue->dbc_iring.trb = in_trb;
> +    xue->dbc_owork.buf = wrk_buf;
> +    xue->dbc_str = str_buf;

Especially the page-sized entities want allocating dynamically here, as
they won't be needed without the command line option requesting the use
of this driver.

> +    xue_open(xue);

No check of return value?

> +    serial_register_uart(SERHND_DBGP, &xue_uart_driver, &xue_uart);
> +}
> +
> +void xue_uart_dump(void)
> +{
> +    struct xue_uart *uart = &xue_uart;
> +    struct xue *xue = &uart->xue;
> +
> +    xue_dump(xue);
> +}

This function looks to be unused (and lacks a declaration).

Jan


^ permalink raw reply	[flat|nested] 23+ messages in thread

* Re: [PATCH v1 02/10] xue: reset XHCI ports when initializing dbc
  2022-06-07 14:30 ` [PATCH v1 02/10] xue: reset XHCI ports when initializing dbc Marek Marczykowski-Górecki
@ 2022-06-15 14:35   ` Jan Beulich
  0 siblings, 0 replies; 23+ messages in thread
From: Jan Beulich @ 2022-06-15 14:35 UTC (permalink / raw)
  To: Marek Marczykowski-Górecki
  Cc: Andrew Cooper, George Dunlap, Julien Grall, Stefano Stabellini,
	Wei Liu, xen-devel

On 07.06.2022 16:30, Marek Marczykowski-Górecki wrote:
> Reset ports, to force host system to re-enumerate devices. Otheriwse it
> will require the cable to be re-plugged, or will wait in the
> "configuring" state indefinitely.
> 
> Trick and code copied from Linux:
> drivers/usb/early/xhci-dbc.c:xdbc_start()->xdbc_reset_debug_port()
> 
> Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>

Just two style nits:

> --- a/xen/drivers/char/xue.c
> +++ b/xen/drivers/char/xue.c
> @@ -60,6 +60,10 @@
>      ((1UL << XUE_PSC_CSC) | (1UL << XUE_PSC_PRC) | (1UL << XUE_PSC_PLC) |      \
>       (1UL << XUE_PSC_CEC))
>  
> +#define     XUE_XHC_EXT_PORT_MAJOR(x)  (((x) >> 24) & 0xff)
> +#define PORT_RESET  (1 << 4)
> +#define PORT_CONNECT  (1 << 0)

Odd multiple blanks on the first of the lines you add.

> @@ -604,6 +608,68 @@ static void xue_init_strings(struct xue *xue, uint32_t *info)
>      info[8] = (4 << 24) | (30 << 16) | (8 << 8) | 6;
>  }
>  
> +static void xue_do_reset_debug_port(struct xue *xue, u32 id, u32 count)
> +{
> +    uint32_t *ops_reg;
> +    uint32_t *portsc;
> +    u32 val, cap_length;
> +    int i;
> +
> +    cap_length = (*(uint32_t*)xue->xhc_mmio) & 0xff;
> +    ops_reg = xue->xhc_mmio + cap_length;
> +
> +    id--;
> +    for ( i = id; i < (id + count); i++ )
> +    {
> +        portsc = ops_reg + 0x100 + i * 0x4;
> +        val = *portsc;
> +        if ( !(val & PORT_CONNECT) )
> +            *portsc = val | PORT_RESET;
> +    }
> +}
> +
> +
> +static void xue_reset_debug_port(struct xue *xue)

Please don't add double blank lines.

Jan


^ permalink raw reply	[flat|nested] 23+ messages in thread

* Re: [PATCH v1 03/10] xue: add support for selecting specific xhci
  2022-06-07 14:30 ` [PATCH v1 03/10] xue: add support for selecting specific xhci Marek Marczykowski-Górecki
@ 2022-06-15 14:40   ` Jan Beulich
  0 siblings, 0 replies; 23+ messages in thread
From: Jan Beulich @ 2022-06-15 14:40 UTC (permalink / raw)
  To: Marek Marczykowski-Górecki
  Cc: Andrew Cooper, George Dunlap, Julien Grall, Stefano Stabellini,
	Wei Liu, xen-devel

On 07.06.2022 16:30, Marek Marczykowski-Górecki wrote:
> --- a/docs/misc/xen-command-line.pandoc
> +++ b/docs/misc/xen-command-line.pandoc
> @@ -721,10 +721,15 @@ Available alternatives, with their meaning, are:
>  
>  ### dbgp
>  > `= ehci[ <integer> | @pci<bus>:<slot>.<func> ]`
> +> `= xue[ <integer> | @pci<bus>:<slot>.<func> ]`
>  
>  Specify the USB controller to use, either by instance number (when going
>  over the PCI busses sequentially) or by PCI device (must be on segment 0).
>  
> +Use `ehci` for EHCI debug port, use `xue` for XHCI debug capability.

Ah, this answers one of my questions on patch 1. But I still think
the option should appear here in patch 1, with this patch extending
it (and its doc).

> --- a/xen/drivers/char/xue.c
> +++ b/xen/drivers/char/xue.c
> @@ -204,6 +204,7 @@ struct xue {
>      void *xhc_mmio;
>  
>      int open;
> +    int xhc_num; /* look for n-th xhc */

unsigned int?

> @@ -252,24 +253,34 @@ static int xue_init_xhc(struct xue *xue)
>      uint64_t bar1;
>      uint64_t devfn;
>  
> -    /*
> -     * Search PCI bus 0 for the xHC. All the host controllers supported so far
> -     * are part of the chipset and are on bus 0.
> -     */
> -    for ( devfn = 0; devfn < 256; devfn++ ) {
> -        uint32_t dev = (devfn & 0xF8) >> 3;
> -        uint32_t fun = devfn & 0x07;
> -        pci_sbdf_t sbdf = PCI_SBDF(0, dev, fun);
> -        uint32_t hdr = pci_conf_read8(sbdf, PCI_HEADER_TYPE);
> -
> -        if ( hdr == 0 || hdr == 0x80 )
> +    if ( xue->sbdf.sbdf == 0 )
> +    {
> +        /*
> +         * Search PCI bus 0 for the xHC. All the host controllers supported so far
> +         * are part of the chipset and are on bus 0.
> +         */
> +        for ( devfn = 0; devfn < 256; devfn++ )
>          {
> -            if ( (pci_conf_read32(sbdf, PCI_CLASS_REVISION) >> 8) == XUE_XHC_CLASSC )
> +            uint32_t dev = (devfn & 0xF8) >> 3;
> +            uint32_t fun = devfn & 0x07;
> +            pci_sbdf_t sbdf = PCI_SBDF(0, dev, fun);
> +            uint32_t hdr = pci_conf_read8(sbdf, PCI_HEADER_TYPE);
> +
> +            if ( hdr == 0 || hdr == 0x80 )
>              {
> -                xue->sbdf = sbdf;
> -                break;
> +                if ( (pci_conf_read32(sbdf, PCI_CLASS_REVISION) >> 8) == XUE_XHC_CLASSC )
> +                {
> +                    if ( xue->xhc_num-- )
> +                        continue;
> +                    xue->sbdf = sbdf;
> +                    break;
> +                }
>              }
>          }
> +    } else {

Nit:

    }
    else
    {

Jan


^ permalink raw reply	[flat|nested] 23+ messages in thread

* Re: [PATCH v1 04/10] ehci-dbgp: fix selecting n-th ehci controller
  2022-06-07 14:30 ` [PATCH v1 04/10] ehci-dbgp: fix selecting n-th ehci controller Marek Marczykowski-Górecki
@ 2022-06-15 14:42   ` Jan Beulich
  0 siblings, 0 replies; 23+ messages in thread
From: Jan Beulich @ 2022-06-15 14:42 UTC (permalink / raw)
  To: Marek Marczykowski-Górecki
  Cc: Andrew Cooper, George Dunlap, Julien Grall, Stefano Stabellini,
	Wei Liu, xen-devel

On 07.06.2022 16:30, Marek Marczykowski-Górecki wrote:
> The ehci<n> number was parsed but ignored.

Oops.

> Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>

This could do with a Fixes: tag. Then
Reviewed-by: Jan Beulich <jbeulich@suse.com>

Jan


^ permalink raw reply	[flat|nested] 23+ messages in thread

* Re: [PATCH v1 01/10] drivers/char: Add support for Xue USB3 debugger
  2022-06-15 14:25   ` Jan Beulich
@ 2022-06-22 15:47     ` Marek Marczykowski-Górecki
  2022-06-23  9:29       ` Jan Beulich
  0 siblings, 1 reply; 23+ messages in thread
From: Marek Marczykowski-Górecki @ 2022-06-22 15:47 UTC (permalink / raw)
  To: Jan Beulich
  Cc: Connor Davis, Andrew Cooper, Roger Pau Monné,
	Wei Liu, George Dunlap, Julien Grall, Stefano Stabellini,
	Connor Davis, xen-devel

[-- Attachment #1: Type: text/plain, Size: 2660 bytes --]

On Wed, Jun 15, 2022 at 04:25:54PM +0200, Jan Beulich wrote:
> On 07.06.2022 16:30, Marek Marczykowski-Górecki wrote:
> > From: Connor Davis <davisc@ainfosec.com>
> > --- /dev/null
> > +++ b/xen/drivers/char/xue.c
> > @@ -0,0 +1,957 @@
> > +/*
> > + * drivers/char/xue.c
> > + *
> > + * Xen port for the xue debugger
> 
> Since even here it's not spelled out - may I ask what "xue" actually
> stands for (assumng it's an acronym)?

Honestly, I don't know. That would be a question to Connor.

> > +/* Supported xHC PCI configurations */
> > +#define XUE_XHC_CLASSC 0xC0330ULL
> 
> While I'm not meaning to fully review the code in this file (for lack
> of knowledge on xhci), the two ULL suffixes above strike me as odd.
> Is there a specific reason these can't just be U?

I don't think so (that's just how it was in xue.h). Will adjust. The
same response applies to many other remarks.

> > +    /* ...we found it, so parse the BAR and map the registers */
> > +    bar0 = pci_conf_read32(xue->sbdf, PCI_BASE_ADDRESS_0);
> > +    bar1 = pci_conf_read32(xue->sbdf, PCI_BASE_ADDRESS_1);
> 
> What if there are multiple?

You mean two 32-bit BARs? I check for that below (refusing to use them).
Anyway, I don't think that's a thing in USB 3.0 controllers.


> > +    /* IO BARs not allowed; BAR must be 64-bit */
> > +    if ( (bar0 & 0x1) != 0 || ((bar0 & 0x6) >> 1) != 2 )

(...)

> > +    memset(xue, 0, sizeof(*xue));
> > +
> > +    xue->dbc_ctx = &ctx;
> > +    xue->dbc_erst = &erst;
> > +    xue->dbc_ering.trb = evt_trb;
> > +    xue->dbc_oring.trb = out_trb;
> > +    xue->dbc_iring.trb = in_trb;
> > +    xue->dbc_owork.buf = wrk_buf;
> > +    xue->dbc_str = str_buf;
> 
> Especially the page-sized entities want allocating dynamically here, as
> they won't be needed without the command line option requesting the use
> of this driver.

Are you okay with changing this only in patch 9, where I restructure those
buffers anyway?

> > +    xue_open(xue);
> 
> No check of return value?

Good catch, will adjust.

> > +    serial_register_uart(SERHND_DBGP, &xue_uart_driver, &xue_uart);
> > +}
> > +
> > +void xue_uart_dump(void)
> > +{
> > +    struct xue_uart *uart = &xue_uart;
> > +    struct xue *xue = &uart->xue;
> > +
> > +    xue_dump(xue);
> > +}
> 
> This function looks to be unused (and lacks a declaration).

It is unused, same as xue_dump(), but is extremely useful when
debugging. Should I put it behind something like #ifdef XUE_DEBUG,
accompanied with a comment about its purpose?

-- 
Best Regards,
Marek Marczykowski-Górecki
Invisible Things Lab

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^ permalink raw reply	[flat|nested] 23+ messages in thread

* Re: [PATCH v1 01/10] drivers/char: Add support for Xue USB3 debugger
  2022-06-22 15:47     ` Marek Marczykowski-Górecki
@ 2022-06-23  9:29       ` Jan Beulich
  2022-07-03 12:17         ` Marek Marczykowski-Górecki
  0 siblings, 1 reply; 23+ messages in thread
From: Jan Beulich @ 2022-06-23  9:29 UTC (permalink / raw)
  To: Marek Marczykowski-Górecki
  Cc: Connor Davis, Andrew Cooper, Roger Pau Monné,
	Wei Liu, George Dunlap, Julien Grall, Stefano Stabellini,
	Connor Davis, xen-devel

On 22.06.2022 17:47, Marek Marczykowski-Górecki wrote:
> On Wed, Jun 15, 2022 at 04:25:54PM +0200, Jan Beulich wrote:
>> On 07.06.2022 16:30, Marek Marczykowski-Górecki wrote:
>>> +    /* ...we found it, so parse the BAR and map the registers */
>>> +    bar0 = pci_conf_read32(xue->sbdf, PCI_BASE_ADDRESS_0);
>>> +    bar1 = pci_conf_read32(xue->sbdf, PCI_BASE_ADDRESS_1);
>>
>> What if there are multiple?
> 
> You mean two 32-bit BARs? I check for that below (refusing to use them).
> Anyway, I don't think that's a thing in USB 3.0 controllers.

No, I mean multiple controllers. When making the remark I didn't know
yet that you'll deal with that in patch 3. A sentence making the
restriction (and its intended resolution) explicit in the description
would help.

>>> +    memset(xue, 0, sizeof(*xue));
>>> +
>>> +    xue->dbc_ctx = &ctx;
>>> +    xue->dbc_erst = &erst;
>>> +    xue->dbc_ering.trb = evt_trb;
>>> +    xue->dbc_oring.trb = out_trb;
>>> +    xue->dbc_iring.trb = in_trb;
>>> +    xue->dbc_owork.buf = wrk_buf;
>>> +    xue->dbc_str = str_buf;
>>
>> Especially the page-sized entities want allocating dynamically here, as
>> they won't be needed without the command line option requesting the use
>> of this driver.
> 
> Are you okay with changing this only in patch 9, where I restructure those
> buffers anyway?

I'm afraid I'll need to make it to patch 9 to answer this question. If
suitable dealt with later, I don't see a fundamental problem, as long
as it's clear then that I will request that this patch be committed in
a batch with that later one, not in isolation.

>>> +    serial_register_uart(SERHND_DBGP, &xue_uart_driver, &xue_uart);
>>> +}
>>> +
>>> +void xue_uart_dump(void)
>>> +{
>>> +    struct xue_uart *uart = &xue_uart;
>>> +    struct xue *xue = &uart->xue;
>>> +
>>> +    xue_dump(xue);
>>> +}
>>
>> This function looks to be unused (and lacks a declaration).
> 
> It is unused, same as xue_dump(), but is extremely useful when
> debugging. Should I put it behind something like #ifdef XUE_DEBUG,
> accompanied with a comment about its purpose?

Yes, please (or any other suitable means to make the functions
disappear from the final binary). The function here then also ought
to be static, I suppose - you're not adding a declaration anywhere
for it to be usable outside of this source file.

Jan


^ permalink raw reply	[flat|nested] 23+ messages in thread

* Re: [PATCH v1 01/10] drivers/char: Add support for Xue USB3 debugger
  2022-06-23  9:29       ` Jan Beulich
@ 2022-07-03 12:17         ` Marek Marczykowski-Górecki
  2022-07-04  6:05           ` Jan Beulich
  0 siblings, 1 reply; 23+ messages in thread
From: Marek Marczykowski-Górecki @ 2022-07-03 12:17 UTC (permalink / raw)
  To: Jan Beulich
  Cc: Connor Davis, Andrew Cooper, Roger Pau Monné,
	Wei Liu, George Dunlap, Julien Grall, Stefano Stabellini,
	Connor Davis, xen-devel

[-- Attachment #1: Type: text/plain, Size: 1710 bytes --]

On Thu, Jun 23, 2022 at 11:29:31AM +0200, Jan Beulich wrote:
> On 22.06.2022 17:47, Marek Marczykowski-Górecki wrote:
> > On Wed, Jun 15, 2022 at 04:25:54PM +0200, Jan Beulich wrote:
> >> On 07.06.2022 16:30, Marek Marczykowski-Górecki wrote:
> >>> +    memset(xue, 0, sizeof(*xue));
> >>> +
> >>> +    xue->dbc_ctx = &ctx;
> >>> +    xue->dbc_erst = &erst;
> >>> +    xue->dbc_ering.trb = evt_trb;
> >>> +    xue->dbc_oring.trb = out_trb;
> >>> +    xue->dbc_iring.trb = in_trb;
> >>> +    xue->dbc_owork.buf = wrk_buf;
> >>> +    xue->dbc_str = str_buf;
> >>
> >> Especially the page-sized entities want allocating dynamically here, as
> >> they won't be needed without the command line option requesting the use
> >> of this driver.
> > 
> > Are you okay with changing this only in patch 9, where I restructure those
> > buffers anyway?
> 
> I'm afraid I'll need to make it to patch 9 to answer this question. If
> suitable dealt with later, I don't see a fundamental problem, as long
> as it's clear then that I will request that this patch be committed in
> a batch with that later one, not in isolation.

This turns out to be rather problematic. xue_uart_init() is called
really early (as it should, to get console as early as possible). It's
before even boot allocator is functioning, so I can't use alloc_boot_pages().
Are there any other options for memory allocations at this point?
We are talking about 58 pages. It isn't much, but isn't exactly nothing
either. Maybe there is way to keep the memory allocated statically as it
is now, but return it to the allocator is xue is _not_ enabled?

-- 
Best Regards,
Marek Marczykowski-Górecki
Invisible Things Lab

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^ permalink raw reply	[flat|nested] 23+ messages in thread

* Re: [PATCH v1 01/10] drivers/char: Add support for Xue USB3 debugger
  2022-07-03 12:17         ` Marek Marczykowski-Górecki
@ 2022-07-04  6:05           ` Jan Beulich
  2022-07-04  9:27             ` Marek Marczykowski-Górecki
  0 siblings, 1 reply; 23+ messages in thread
From: Jan Beulich @ 2022-07-04  6:05 UTC (permalink / raw)
  To: Marek Marczykowski-Górecki
  Cc: Connor Davis, Andrew Cooper, Roger Pau Monné,
	Wei Liu, George Dunlap, Julien Grall, Stefano Stabellini,
	Connor Davis, xen-devel

On 03.07.2022 14:17, Marek Marczykowski-Górecki wrote:
> On Thu, Jun 23, 2022 at 11:29:31AM +0200, Jan Beulich wrote:
>> On 22.06.2022 17:47, Marek Marczykowski-Górecki wrote:
>>> On Wed, Jun 15, 2022 at 04:25:54PM +0200, Jan Beulich wrote:
>>>> On 07.06.2022 16:30, Marek Marczykowski-Górecki wrote:
>>>>> +    memset(xue, 0, sizeof(*xue));
>>>>> +
>>>>> +    xue->dbc_ctx = &ctx;
>>>>> +    xue->dbc_erst = &erst;
>>>>> +    xue->dbc_ering.trb = evt_trb;
>>>>> +    xue->dbc_oring.trb = out_trb;
>>>>> +    xue->dbc_iring.trb = in_trb;
>>>>> +    xue->dbc_owork.buf = wrk_buf;
>>>>> +    xue->dbc_str = str_buf;
>>>>
>>>> Especially the page-sized entities want allocating dynamically here, as
>>>> they won't be needed without the command line option requesting the use
>>>> of this driver.
>>>
>>> Are you okay with changing this only in patch 9, where I restructure those
>>> buffers anyway?
>>
>> I'm afraid I'll need to make it to patch 9 to answer this question. If
>> suitable dealt with later, I don't see a fundamental problem, as long
>> as it's clear then that I will request that this patch be committed in
>> a batch with that later one, not in isolation.
> 
> This turns out to be rather problematic. xue_uart_init() is called
> really early (as it should, to get console as early as possible). It's
> before even boot allocator is functioning, so I can't use alloc_boot_pages().
> Are there any other options for memory allocations at this point?

No "neat" ones. Stealing directly from E820 could be an option, but
would of course be heavily x86-centric.

> We are talking about 58 pages. It isn't much, but isn't exactly nothing
> either. Maybe there is way to keep the memory allocated statically as it
> is now, but return it to the allocator is xue is _not_ enabled?

Well, yes, treating them like .init.data would seem to be the least bad
alternative then, at least for now. Down the road we may want to generalize
what's needed here, as there are other full-page or larger memory areas
which are used only under certain conditions. We may e.g. want to introduce
an approach similar to Linux'es .brk section (recently renamed to .brk..bss
iirc). If a non-generalized approach ends up looking too ugly, I'd be okay
with keeping things as they're now, just with a respective justification
added to the patch description.

Jan


^ permalink raw reply	[flat|nested] 23+ messages in thread

* Re: [PATCH v1 01/10] drivers/char: Add support for Xue USB3 debugger
  2022-07-04  6:05           ` Jan Beulich
@ 2022-07-04  9:27             ` Marek Marczykowski-Górecki
  2022-07-04  9:36               ` Jan Beulich
  0 siblings, 1 reply; 23+ messages in thread
From: Marek Marczykowski-Górecki @ 2022-07-04  9:27 UTC (permalink / raw)
  To: Jan Beulich
  Cc: Connor Davis, Andrew Cooper, Roger Pau Monné,
	Wei Liu, George Dunlap, Julien Grall, Stefano Stabellini,
	Connor Davis, xen-devel

[-- Attachment #1: Type: text/plain, Size: 3087 bytes --]

On Mon, Jul 04, 2022 at 08:05:06AM +0200, Jan Beulich wrote:
> On 03.07.2022 14:17, Marek Marczykowski-Górecki wrote:
> > On Thu, Jun 23, 2022 at 11:29:31AM +0200, Jan Beulich wrote:
> >> On 22.06.2022 17:47, Marek Marczykowski-Górecki wrote:
> >>> On Wed, Jun 15, 2022 at 04:25:54PM +0200, Jan Beulich wrote:
> >>>> On 07.06.2022 16:30, Marek Marczykowski-Górecki wrote:
> >>>>> +    memset(xue, 0, sizeof(*xue));
> >>>>> +
> >>>>> +    xue->dbc_ctx = &ctx;
> >>>>> +    xue->dbc_erst = &erst;
> >>>>> +    xue->dbc_ering.trb = evt_trb;
> >>>>> +    xue->dbc_oring.trb = out_trb;
> >>>>> +    xue->dbc_iring.trb = in_trb;
> >>>>> +    xue->dbc_owork.buf = wrk_buf;
> >>>>> +    xue->dbc_str = str_buf;
> >>>>
> >>>> Especially the page-sized entities want allocating dynamically here, as
> >>>> they won't be needed without the command line option requesting the use
> >>>> of this driver.
> >>>
> >>> Are you okay with changing this only in patch 9, where I restructure those
> >>> buffers anyway?
> >>
> >> I'm afraid I'll need to make it to patch 9 to answer this question. If
> >> suitable dealt with later, I don't see a fundamental problem, as long
> >> as it's clear then that I will request that this patch be committed in
> >> a batch with that later one, not in isolation.
> > 
> > This turns out to be rather problematic. xue_uart_init() is called
> > really early (as it should, to get console as early as possible). It's
> > before even boot allocator is functioning, so I can't use alloc_boot_pages().
> > Are there any other options for memory allocations at this point?
> 
> No "neat" ones. Stealing directly from E820 could be an option, but
> would of course be heavily x86-centric.
> 
> > We are talking about 58 pages. It isn't much, but isn't exactly nothing
> > either. Maybe there is way to keep the memory allocated statically as it
> > is now, but return it to the allocator is xue is _not_ enabled?
> 
> Well, yes, treating them like .init.data would seem to be the least bad
> alternative then, at least for now. Down the road we may want to generalize
> what's needed here, as there are other full-page or larger memory areas
> which are used only under certain conditions. We may e.g. want to introduce
> an approach similar to Linux'es .brk section (recently renamed to .brk..bss
> iirc). If a non-generalized approach ends up looking too ugly, I'd be okay
> with keeping things as they're now, just with a respective justification
> added to the patch description.

Looking at it, I see another issue - Xen uses superpages, so I'd either
need to:
 - reserve the whole superpage to be able to release it later (waste 6
   pages if xue is used), or
 - shatter superpage when releasing unused xue buffers

First one is probably less bad. But maybe, instead of doing all this,
add xue to the menuconfig (make the prompt visible) with appropriate
note about wasting 58 pages when built-in but not enabled. What do you
think?

-- 
Best Regards,
Marek Marczykowski-Górecki
Invisible Things Lab

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^ permalink raw reply	[flat|nested] 23+ messages in thread

* Re: [PATCH v1 01/10] drivers/char: Add support for Xue USB3 debugger
  2022-07-04  9:27             ` Marek Marczykowski-Górecki
@ 2022-07-04  9:36               ` Jan Beulich
  0 siblings, 0 replies; 23+ messages in thread
From: Jan Beulich @ 2022-07-04  9:36 UTC (permalink / raw)
  To: Marek Marczykowski-Górecki
  Cc: Connor Davis, Andrew Cooper, Roger Pau Monné,
	Wei Liu, George Dunlap, Julien Grall, Stefano Stabellini,
	Connor Davis, xen-devel

On 04.07.2022 11:27, Marek Marczykowski-Górecki wrote:
> On Mon, Jul 04, 2022 at 08:05:06AM +0200, Jan Beulich wrote:
>> On 03.07.2022 14:17, Marek Marczykowski-Górecki wrote:
>>> On Thu, Jun 23, 2022 at 11:29:31AM +0200, Jan Beulich wrote:
>>>> On 22.06.2022 17:47, Marek Marczykowski-Górecki wrote:
>>>>> On Wed, Jun 15, 2022 at 04:25:54PM +0200, Jan Beulich wrote:
>>>>>> On 07.06.2022 16:30, Marek Marczykowski-Górecki wrote:
>>>>>>> +    memset(xue, 0, sizeof(*xue));
>>>>>>> +
>>>>>>> +    xue->dbc_ctx = &ctx;
>>>>>>> +    xue->dbc_erst = &erst;
>>>>>>> +    xue->dbc_ering.trb = evt_trb;
>>>>>>> +    xue->dbc_oring.trb = out_trb;
>>>>>>> +    xue->dbc_iring.trb = in_trb;
>>>>>>> +    xue->dbc_owork.buf = wrk_buf;
>>>>>>> +    xue->dbc_str = str_buf;
>>>>>>
>>>>>> Especially the page-sized entities want allocating dynamically here, as
>>>>>> they won't be needed without the command line option requesting the use
>>>>>> of this driver.
>>>>>
>>>>> Are you okay with changing this only in patch 9, where I restructure those
>>>>> buffers anyway?
>>>>
>>>> I'm afraid I'll need to make it to patch 9 to answer this question. If
>>>> suitable dealt with later, I don't see a fundamental problem, as long
>>>> as it's clear then that I will request that this patch be committed in
>>>> a batch with that later one, not in isolation.
>>>
>>> This turns out to be rather problematic. xue_uart_init() is called
>>> really early (as it should, to get console as early as possible). It's
>>> before even boot allocator is functioning, so I can't use alloc_boot_pages().
>>> Are there any other options for memory allocations at this point?
>>
>> No "neat" ones. Stealing directly from E820 could be an option, but
>> would of course be heavily x86-centric.
>>
>>> We are talking about 58 pages. It isn't much, but isn't exactly nothing
>>> either. Maybe there is way to keep the memory allocated statically as it
>>> is now, but return it to the allocator is xue is _not_ enabled?
>>
>> Well, yes, treating them like .init.data would seem to be the least bad
>> alternative then, at least for now. Down the road we may want to generalize
>> what's needed here, as there are other full-page or larger memory areas
>> which are used only under certain conditions. We may e.g. want to introduce
>> an approach similar to Linux'es .brk section (recently renamed to .brk..bss
>> iirc). If a non-generalized approach ends up looking too ugly, I'd be okay
>> with keeping things as they're now, just with a respective justification
>> added to the patch description.
> 
> Looking at it, I see another issue - Xen uses superpages, so I'd either
> need to:
>  - reserve the whole superpage to be able to release it later (waste 6
>    pages if xue is used), or
>  - shatter superpage when releasing unused xue buffers

That's part of the reason for my desire to generalize this.

> First one is probably less bad. But maybe, instead of doing all this,
> add xue to the menuconfig (make the prompt visible) with appropriate
> note about wasting 58 pages when built-in but not enabled. What do you
> think?

I don't mind it being done this way for now.

Jan


^ permalink raw reply	[flat|nested] 23+ messages in thread

* RE: [PATCH v1 00/10] Add Xue - console over USB 3 Debug Capability
  2022-06-07 14:30 [PATCH v1 00/10] Add Xue - console over USB 3 Debug Capability Marek Marczykowski-Górecki
                   ` (10 preceding siblings ...)
  2022-06-07 18:48 ` [PATCH v1 00/10] Add Xue - console over USB 3 Debug Capability Tamas K Lengyel
@ 2022-07-06  7:30 ` Henry Wang
  11 siblings, 0 replies; 23+ messages in thread
From: Henry Wang @ 2022-07-06  7:30 UTC (permalink / raw)
  To: Marek Marczykowski-Górecki, xen-devel
  Cc: Andrew Cooper, George Dunlap, Jan Beulich, Julien Grall,
	Stefano Stabellini, Wei Liu, Roger Pau Monné,
	Paul Durrant, Kevin Tian, Connor Davis

Hi,

It seems that this series has been stale for more than a month, with:

Patch #1 #2 #3 needs actions from the author.
Patch #4 reviewed.
Patch #5 to #10 needs feedback from maintainers.

So sending this email as a gentle reminder. Thanks!

Kind regards,
Henry

> -----Original Message-----
> Subject: [PATCH v1 00/10] Add Xue - console over USB 3 Debug Capability
> 
> This is integration of https://github.com/connojd/xue into mainline Xen.
> This patch series includes several patches that I made in the process, some
> are
> very loosely related.
> 
> The driver developed by Connor supports output-only console via USB3
> debug
> capability. The capability is designed to operate mostly independently of
> normal XHCI driver, so this patch series allows dom0 to drive standard USB3
> controller part, while Xen uses DbC for console output.
> 
> Changes since RFC:
>  - move the driver to xue.c, remove non-Xen parts, remove now unneeded
> abstraction
>  - adjust for Xen code style
>  - build for x86 only
>  - drop patch hidding the device from dom0
> 
> Cc: Andrew Cooper <andrew.cooper3@citrix.com>
> Cc: George Dunlap <george.dunlap@citrix.com>
> Cc: Jan Beulich <jbeulich@suse.com>
> Cc: Julien Grall <julien@xen.org>
> Cc: Stefano Stabellini <sstabellini@kernel.org>
> Cc: Wei Liu <wl@xen.org>
> Cc: "Roger Pau Monné" <roger.pau@citrix.com>
> Cc: Paul Durrant <paul@xen.org>
> Cc: Kevin Tian <kevin.tian@intel.com>
> Cc: Connor Davis <connojdavis@gmail.com>
> 
> Connor Davis (1):
>   drivers/char: Add support for Xue USB3 debugger
> 
> Marek Marczykowski-Górecki (9):
>   xue: reset XHCI ports when initializing dbc
>   xue: add support for selecting specific xhci
>   ehci-dbgp: fix selecting n-th ehci controller
>   console: support multiple serial console simultaneously
>   IOMMU: add common API for device reserved memory
>   IOMMU/VT-d: wire common device reserved memory API
>   IOMMU/AMD: wire common device reserved memory API
>   xue: mark DMA buffers as reserved for the device
>   xue: allow driving the rest of XHCI by a domain while Xen uses DbC
> 
>  docs/misc/xen-command-line.pandoc        |    5 +-
>  xen/arch/x86/Kconfig                     |    1 +-
>  xen/arch/x86/include/asm/fixmap.h        |    4 +-
>  xen/arch/x86/setup.c                     |    1 +-
>  xen/drivers/char/Kconfig                 |    7 +-
>  xen/drivers/char/Makefile                |    1 +-
>  xen/drivers/char/console.c               |   58 +-
>  xen/drivers/char/ehci-dbgp.c             |    2 +-
>  xen/drivers/char/xue.c                   | 1089 +++++++++++++++++++++++-
>  xen/drivers/passthrough/amd/iommu_acpi.c |   16 +-
>  xen/drivers/passthrough/iommu.c          |   40 +-
>  xen/drivers/passthrough/vtd/dmar.c       |  203 ++--
>  xen/include/xen/iommu.h                  |   11 +-
>  xen/include/xen/serial.h                 |    1 +-
>  14 files changed, 1342 insertions(+), 97 deletions(-)
>  create mode 100644 xen/drivers/char/xue.c
> 
> base-commit: 49dd52fb1311dadab29f6634d0bc1f4c022c357a
> --
> git-series 0.9.1


^ permalink raw reply	[flat|nested] 23+ messages in thread

end of thread, other threads:[~2022-07-06  7:38 UTC | newest]

Thread overview: 23+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-06-07 14:30 [PATCH v1 00/10] Add Xue - console over USB 3 Debug Capability Marek Marczykowski-Górecki
2022-06-07 14:30 ` [PATCH v1 01/10] drivers/char: Add support for Xue USB3 debugger Marek Marczykowski-Górecki
2022-06-15 14:25   ` Jan Beulich
2022-06-22 15:47     ` Marek Marczykowski-Górecki
2022-06-23  9:29       ` Jan Beulich
2022-07-03 12:17         ` Marek Marczykowski-Górecki
2022-07-04  6:05           ` Jan Beulich
2022-07-04  9:27             ` Marek Marczykowski-Górecki
2022-07-04  9:36               ` Jan Beulich
2022-06-07 14:30 ` [PATCH v1 02/10] xue: reset XHCI ports when initializing dbc Marek Marczykowski-Górecki
2022-06-15 14:35   ` Jan Beulich
2022-06-07 14:30 ` [PATCH v1 03/10] xue: add support for selecting specific xhci Marek Marczykowski-Górecki
2022-06-15 14:40   ` Jan Beulich
2022-06-07 14:30 ` [PATCH v1 04/10] ehci-dbgp: fix selecting n-th ehci controller Marek Marczykowski-Górecki
2022-06-15 14:42   ` Jan Beulich
2022-06-07 14:30 ` [PATCH v1 05/10] console: support multiple serial console simultaneously Marek Marczykowski-Górecki
2022-06-07 14:30 ` [PATCH v1 06/10] IOMMU: add common API for device reserved memory Marek Marczykowski-Górecki
2022-06-07 14:30 ` [PATCH v1 07/10] IOMMU/VT-d: wire common device reserved memory API Marek Marczykowski-Górecki
2022-06-07 14:30 ` [PATCH v1 08/10] IOMMU/AMD: " Marek Marczykowski-Górecki
2022-06-07 14:30 ` [PATCH v1 09/10] xue: mark DMA buffers as reserved for the device Marek Marczykowski-Górecki
2022-06-07 14:30 ` [PATCH v1 10/10] xue: allow driving the rest of XHCI by a domain while Xen uses DbC Marek Marczykowski-Górecki
2022-06-07 18:48 ` [PATCH v1 00/10] Add Xue - console over USB 3 Debug Capability Tamas K Lengyel
2022-07-06  7:30 ` Henry Wang

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