git: 563fd2240e13 - main - bhyve: export funcs for read/write pci config

The branch main has been updated by manu:

URL: https://cgit.FreeBSD.org/src/commit/?id=563fd2240e13cfb53f6e5d50e9d1dc738b7c441e

commit 563fd2240e13cfb53f6e5d50e9d1dc738b7c441e
Author:     Corvin Köhne <CorvinK@beckhoff.com>
AuthorDate: 2022-03-10 10:26:19 +0000
Commit:     Emmanuel Vadot <manu@FreeBSD.org>
CommitDate: 2022-03-10 11:30:02 +0000

    bhyve: export funcs for read/write pci config
    
    Export functions for reading and writing the pci config space from passthru
    device to be used by other devices.
    This is required for lpc devices to set their vendor/device ids to their
    physical values.
    Otherwise, GPU passthrough for integrated Intel GPUs won't work properly.
    
    Differential Revision:  https://reviews.freebsd.org/D33769
    Reviewed by:    markj
    Sponsored by:   Beckhoff Automation GmbH & Co. KG
    MFC after:      1 month
---
 usr.sbin/bhyve/pci_passthru.c | 62 +++++++++++++++++++++++++------------------
 usr.sbin/bhyve/pci_passthru.h | 15 +++++++++++
 2 files changed, 51 insertions(+), 26 deletions(-)

diff --git a/usr.sbin/bhyve/pci_passthru.c b/usr.sbin/bhyve/pci_passthru.c
index 725ae4fbdb91..fdc0c38ef0c7 100644
--- a/usr.sbin/bhyve/pci_passthru.c
+++ b/usr.sbin/bhyve/pci_passthru.c
@@ -61,12 +61,11 @@ __FBSDID("$FreeBSD$");
 #include <unistd.h>
 
 #include <machine/vmm.h>
-#include <vmmapi.h>
 
 #include "config.h"
 #include "debug.h"
-#include "pci_emul.h"
 #include "mem.h"
+#include "pci_passthru.h"
 
 #ifndef _PATH_DEVPCI
 #define	_PATH_DEVPCI	"/dev/pci"
@@ -115,9 +114,36 @@ msi_caplen(int msgctrl)
 	return (len);
 }
 
-static uint32_t
+static int
+pcifd_init() {
+	pcifd = open(_PATH_DEVPCI, O_RDWR, 0);
+	if (pcifd < 0) {
+		warn("failed to open %s", _PATH_DEVPCI);
+		return (1);
+	}
+
+#ifndef WITHOUT_CAPSICUM
+	cap_rights_t pcifd_rights;
+	cap_rights_init(&pcifd_rights, CAP_IOCTL, CAP_READ, CAP_WRITE);
+	if (caph_rights_limit(pcifd, &pcifd_rights) == -1)
+		errx(EX_OSERR, "Unable to apply rights for sandbox");
+
+	const cap_ioctl_t pcifd_ioctls[] = { PCIOCREAD, PCIOCWRITE, PCIOCGETBAR,
+		PCIOCBARIO, PCIOCBARMMAP };
+	if (caph_ioctls_limit(pcifd, pcifd_ioctls, nitems(pcifd_ioctls)) == -1)
+		errx(EX_OSERR, "Unable to apply rights for sandbox");
+#endif
+
+	return (0);
+}
+
+uint32_t
 read_config(const struct pcisel *sel, long reg, int width)
 {
+	if (pcifd < 0 && pcifd_init()) {
+		return (0);
+	}
+
 	struct pci_io pi;
 
 	bzero(&pi, sizeof(pi));
@@ -131,9 +157,13 @@ read_config(const struct pcisel *sel, long reg, int width)
 		return (pi.pi_data);
 }
 
-static void
+void
 write_config(const struct pcisel *sel, long reg, int width, uint32_t data)
 {
+	if (pcifd < 0 && pcifd_init()) {
+		return;
+	}
+
 	struct pci_io pi;
 
 	bzero(&pi, sizeof(pi));
@@ -638,40 +668,20 @@ passthru_init(struct vmctx *ctx, struct pci_devinst *pi, nvlist_t *nvl)
 	int bus, slot, func, error, memflags;
 	struct passthru_softc *sc;
 	const char *value;
-#ifndef WITHOUT_CAPSICUM
-	cap_rights_t rights;
-	cap_ioctl_t pci_ioctls[] =
-	    { PCIOCREAD, PCIOCWRITE, PCIOCGETBAR, PCIOCBARIO, PCIOCBARMMAP };
-#endif
 
 	sc = NULL;
 	error = 1;
 
-#ifndef WITHOUT_CAPSICUM
-	cap_rights_init(&rights, CAP_IOCTL, CAP_READ, CAP_WRITE);
-#endif
-
 	memflags = vm_get_memflags(ctx);
 	if (!(memflags & VM_MEM_F_WIRED)) {
 		warnx("passthru requires guest memory to be wired");
 		return (error);
 	}
 
-	if (pcifd < 0) {
-		pcifd = open(_PATH_DEVPCI, O_RDWR, 0);
-		if (pcifd < 0) {
-			warn("failed to open %s", _PATH_DEVPCI);
-			return (error);
-		}
+	if (pcifd < 0 && pcifd_init()) {
+		return (error);
 	}
 
-#ifndef WITHOUT_CAPSICUM
-	if (caph_rights_limit(pcifd, &rights) == -1)
-		errx(EX_OSERR, "Unable to apply rights for sandbox");
-	if (caph_ioctls_limit(pcifd, pci_ioctls, nitems(pci_ioctls)) == -1)
-		errx(EX_OSERR, "Unable to apply rights for sandbox");
-#endif
-
 #define GET_INT_CONFIG(var, name) do {					\
 	value = get_config_value_node(nvl, name);			\
 	if (value == NULL) {						\
diff --git a/usr.sbin/bhyve/pci_passthru.h b/usr.sbin/bhyve/pci_passthru.h
new file mode 100644
index 000000000000..bdc8dc3cd0e2
--- /dev/null
+++ b/usr.sbin/bhyve/pci_passthru.h
@@ -0,0 +1,15 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+ *
+ * Copyright (c) 2020 Beckhoff Automation GmbH & Co. KG
+ * Author: Corvin Köhne <c.koehne@beckhoff.com>
+ */
+
+#pragma once
+
+#include <vmmapi.h>
+
+#include "pci_emul.h"
+
+uint32_t read_config(const struct pcisel *sel, long reg, int width);
+void write_config(const struct pcisel *sel, long reg, int width, uint32_t data);