git: 0ad27bd40b35 - stable/13 - bhyve: add hook for PCI header of passthru devices

The branch stable/13 has been updated by corvink:

URL: https://cgit.FreeBSD.org/src/commit/?id=0ad27bd40b351403a6fd0b58eafa98a43407cc83

commit 0ad27bd40b351403a6fd0b58eafa98a43407cc83
Author:     Corvin Köhne <corvink@FreeBSD.org>
AuthorDate: 2021-09-07 11:42:25 +0000
Commit:     Corvin Köhne <corvink@FreeBSD.org>
CommitDate: 2023-04-28 07:28:34 +0000

    bhyve: add hook for PCI header of passthru devices
    
    Most register of the PCI header are either constant values or require
    emulation anyway. The command and status register are the only exception which
    require hardware access. So, we're adding an emulation handler for all
    other register.
    
    As this emulation handler will be reused by some future features like
    GPU passthrough, we directly export it.
    
    Reviewed by:            markj
    MFC after:              1 week
    Sponsored by:           Beckhoff Automation GmbH & Co. KG
    Differential Revision:  https://reviews.freebsd.org/D33010
    
    (cherry picked from commit b6e67875a3e5bc706fe37565e464c61fe7833846)
---
 usr.sbin/bhyve/pci_passthru.c | 71 +++++++++++++++++++++++++------------------
 usr.sbin/bhyve/pci_passthru.h |  4 +++
 2 files changed, 45 insertions(+), 30 deletions(-)

diff --git a/usr.sbin/bhyve/pci_passthru.c b/usr.sbin/bhyve/pci_passthru.c
index 79068ad9b6da..b214021998d2 100644
--- a/usr.sbin/bhyve/pci_passthru.c
+++ b/usr.sbin/bhyve/pci_passthru.c
@@ -603,6 +603,7 @@ cfginit(struct pci_devinst *pi, int bus, int slot, int func)
 {
 	int error;
 	struct passthru_softc *sc;
+	uint8_t intline, intpin;
 
 	error = 1;
 	sc = pi->pi_arg;
@@ -612,6 +613,19 @@ cfginit(struct pci_devinst *pi, int bus, int slot, int func)
 	sc->psc_sel.pc_dev = slot;
 	sc->psc_sel.pc_func = func;
 
+	/*
+	 * Copy physical PCI header to virtual config space. INTLINE and INTPIN
+	 * shouldn't be aligned with their physical value and they are already set by
+	 * pci_emul_init().
+	 */
+	intline = pci_get_cfgdata8(pi, PCIR_INTLINE);
+	intpin = pci_get_cfgdata8(pi, PCIR_INTPIN);
+	for (int i = 0; i <= PCIR_MAXLAT; i += 4) {
+		pci_set_cfgdata32(pi, i, read_config(&sc->psc_sel, i, 4));
+	}
+	pci_set_cfgdata8(pi, PCIR_INTLINE, intline);
+	pci_set_cfgdata8(pi, PCIR_INTPIN, intpin);
+
 	if (cfginitmsi(sc) != 0) {
 		warnx("failed to initialize MSI for PCI %d/%d/%d",
 		    bus, slot, func);
@@ -876,6 +890,15 @@ passthru_init(struct pci_devinst *pi, nvlist_t *nvl)
             get_config_value_node(nvl, "rom"))) != 0)
 		goto done;
 
+	/* Emulate most PCI header register. */
+	if ((error = set_pcir_handler(sc, 0, PCIR_MAXLAT + 1,
+	    passthru_cfgread_emulate, passthru_cfgwrite_emulate)) != 0)
+		goto done;
+
+	/* Allow access to the physical command and status register. */
+	if ((error = set_pcir_handler(sc, PCIR_COMMAND, 0x04, NULL, NULL)) != 0)
+		goto done;
+
 	error = 0;		/* success */
 done:
 	if (error) {
@@ -885,16 +908,6 @@ done:
 	return (error);
 }
 
-static int
-bar_access(int coff)
-{
-	if ((coff >= PCIR_BAR(0) && coff < PCIR_BAR(PCI_BARMAX + 1)) ||
-	    coff == PCIR_BIOS)
-		return (1);
-	else
-		return (0);
-}
-
 static int
 msicap_access(struct passthru_softc *sc, int coff)
 {
@@ -926,23 +939,11 @@ passthru_cfgread_default(struct passthru_softc *sc,
     struct pci_devinst *pi __unused, int coff, int bytes, uint32_t *rv)
 {
 	/*
-	 * PCI BARs and MSI capability is emulated.
+	 * MSI capability is emulated.
 	 */
-	if (bar_access(coff) || msicap_access(sc, coff) ||
-	    msixcap_access(sc, coff))
+	if (msicap_access(sc, coff) || msixcap_access(sc, coff))
 		return (-1);
 
-#ifdef LEGACY_SUPPORT
-	/*
-	 * Emulate PCIR_CAP_PTR if this device does not support MSI capability
-	 * natively.
-	 */
-	if (sc->psc_msi.emulated) {
-		if (coff >= PCIR_CAP_PTR && coff < PCIR_CAP_PTR + 4)
-			return (-1);
-	}
-#endif
-
 	/*
 	 * Emulate the command register.  If a single read reads both the
 	 * command and status registers, read the status register from the
@@ -962,6 +963,14 @@ passthru_cfgread_default(struct passthru_softc *sc,
 	return (0);
 }
 
+int
+passthru_cfgread_emulate(struct passthru_softc *sc __unused,
+    struct pci_devinst *pi __unused, int coff __unused, int bytes __unused,
+    uint32_t *rv __unused)
+{
+	return (-1);
+}
+
 static int
 passthru_cfgread(struct pci_devinst *pi, int coff, int bytes, uint32_t *rv)
 {
@@ -982,12 +991,6 @@ passthru_cfgwrite_default(struct passthru_softc *sc, struct pci_devinst *pi,
 	int error, msix_table_entries, i;
 	uint16_t cmd_old;
 
-	/*
-	 * PCI BARs are emulated
-	 */
-	if (bar_access(coff))
-		return (-1);
-
 	/*
 	 * MSI capability is emulated
 	 */
@@ -1054,6 +1057,14 @@ passthru_cfgwrite_default(struct passthru_softc *sc, struct pci_devinst *pi,
 	return (0);
 }
 
+int
+passthru_cfgwrite_emulate(struct passthru_softc *sc __unused,
+    struct pci_devinst *pi __unused, int coff __unused, int bytes __unused,
+    uint32_t val __unused)
+{
+	return (-1);
+}
+
 static int
 passthru_cfgwrite(struct pci_devinst *pi, int coff, int bytes, uint32_t val)
 {
diff --git a/usr.sbin/bhyve/pci_passthru.h b/usr.sbin/bhyve/pci_passthru.h
index f6ce2d4b85ab..e999e84f85f2 100644
--- a/usr.sbin/bhyve/pci_passthru.h
+++ b/usr.sbin/bhyve/pci_passthru.h
@@ -20,5 +20,9 @@ typedef int (*cfgwrite_handler)(struct passthru_softc *sc,
 
 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);
+int passthru_cfgread_emulate(struct passthru_softc *sc, struct pci_devinst *pi,
+    int coff, int bytes, uint32_t *rv);
+int passthru_cfgwrite_emulate(struct passthru_softc *sc, struct pci_devinst *pi,
+    int coff, int bytes, uint32_t val);
 int set_pcir_handler(struct passthru_softc *sc, int reg, int len,
     cfgread_handler rhandler, cfgwrite_handler whandler);