git: 847adbb116fb - stable/13 - bhyve: define array to protect passthru regs

The branch stable/13 has been updated by corvink:

URL: https://cgit.FreeBSD.org/src/commit/?id=847adbb116fbc1de0c44ff57ab3b2a843c5f3c94

commit 847adbb116fbc1de0c44ff57ab3b2a843c5f3c94
Author:     Corvin Köhne <corvink@FreeBSD.org>
AuthorDate: 2021-03-19 12:48:34 +0000
Commit:     Corvin Köhne <corvink@FreeBSD.org>
CommitDate: 2023-04-28 07:28:34 +0000

    bhyve: define array to protect passthru regs
    
    GPU passthrough requires a special handling of some PCI config register.
    Therefore, we need a flexible approach for implementing it. Adding an
    array of handler meets this condition.
    
    Start by using the default handler for all accesses to the PCI config
    space. In upcoming commits, we can start to split the default handler
    into several handler for each register that requires emulation.
    
    Reviewed by:            markj
    MFC after:              1 week
    Sponsored by:           Beckhoff Automation GmbH & Co. KG
    Differential Revision:  https://reviews.freebsd.org/D39291
    
    (cherry picked from commit 931bb7bf1c8f90f3303b5291e4868c587f9364e7)
---
 usr.sbin/bhyve/pci_passthru.c | 57 +++++++++++++++++++++++++++++++++++++------
 usr.sbin/bhyve/pci_passthru.h |  9 +++++++
 2 files changed, 58 insertions(+), 8 deletions(-)

diff --git a/usr.sbin/bhyve/pci_passthru.c b/usr.sbin/bhyve/pci_passthru.c
index f42bbbda655f..79068ad9b6da 100644
--- a/usr.sbin/bhyve/pci_passthru.c
+++ b/usr.sbin/bhyve/pci_passthru.c
@@ -93,6 +93,9 @@ struct passthru_softc {
 		int		capoff;
 	} psc_msix;
 	struct pcisel psc_sel;
+
+	cfgread_handler psc_pcir_rhandler[PCI_REGMAX + 1];
+	cfgwrite_handler psc_pcir_whandler[PCI_REGMAX + 1];
 };
 
 static int
@@ -643,6 +646,23 @@ done:
 	return (error);
 }
 
+int
+set_pcir_handler(struct passthru_softc *sc, int reg, int len,
+    cfgread_handler rhandler, cfgwrite_handler whandler)
+{
+	if (reg > PCI_REGMAX || reg + len > PCI_REGMAX + 1)
+		return (-1);
+
+	for (int i = reg; i < reg + len; ++i) {
+		assert(sc->psc_pcir_rhandler[i] == NULL || rhandler == NULL);
+		assert(sc->psc_pcir_whandler[i] == NULL || whandler == NULL);
+		sc->psc_pcir_rhandler[i] = rhandler;
+		sc->psc_pcir_whandler[i] = whandler;
+	}
+
+	return (0);
+}
+
 static int
 passthru_legacy_config(nvlist_t *nvl, const char *opts)
 {
@@ -902,12 +922,9 @@ msixcap_access(struct passthru_softc *sc, int coff)
 }
 
 static int
-passthru_cfgread(struct pci_devinst *pi, int coff, int bytes, uint32_t *rv)
+passthru_cfgread_default(struct passthru_softc *sc,
+    struct pci_devinst *pi __unused, int coff, int bytes, uint32_t *rv)
 {
-	struct passthru_softc *sc;
-
-	sc = pi->pi_arg;
-
 	/*
 	 * PCI BARs and MSI capability is emulated.
 	 */
@@ -946,14 +963,25 @@ passthru_cfgread(struct pci_devinst *pi, int coff, int bytes, uint32_t *rv)
 }
 
 static int
-passthru_cfgwrite(struct pci_devinst *pi, int coff, int bytes, uint32_t val)
+passthru_cfgread(struct pci_devinst *pi, int coff, int bytes, uint32_t *rv)
 {
-	int error, msix_table_entries, i;
 	struct passthru_softc *sc;
-	uint16_t cmd_old;
 
 	sc = pi->pi_arg;
 
+	if (sc->psc_pcir_rhandler[coff] != NULL)
+		return (sc->psc_pcir_rhandler[coff](sc, pi, coff, bytes, rv));
+
+	return (passthru_cfgread_default(sc, pi, coff, bytes, rv));
+}
+
+static int
+passthru_cfgwrite_default(struct passthru_softc *sc, struct pci_devinst *pi,
+    int coff, int bytes, uint32_t val)
+{
+	int error, msix_table_entries, i;
+	uint16_t cmd_old;
+
 	/*
 	 * PCI BARs are emulated
 	 */
@@ -1026,6 +1054,19 @@ passthru_cfgwrite(struct pci_devinst *pi, int coff, int bytes, uint32_t val)
 	return (0);
 }
 
+static int
+passthru_cfgwrite(struct pci_devinst *pi, int coff, int bytes, uint32_t val)
+{
+	struct passthru_softc *sc;
+
+	sc = pi->pi_arg;
+
+	if (sc->psc_pcir_whandler[coff] != NULL)
+		return (sc->psc_pcir_whandler[coff](sc, pi, coff, bytes, val));
+
+	return (passthru_cfgwrite_default(sc, pi, coff, bytes, val));
+}
+
 static void
 passthru_write(struct pci_devinst *pi, int baridx, uint64_t offset, int size,
     uint64_t value)
diff --git a/usr.sbin/bhyve/pci_passthru.h b/usr.sbin/bhyve/pci_passthru.h
index bdc8dc3cd0e2..f6ce2d4b85ab 100644
--- a/usr.sbin/bhyve/pci_passthru.h
+++ b/usr.sbin/bhyve/pci_passthru.h
@@ -11,5 +11,14 @@
 
 #include "pci_emul.h"
 
+struct passthru_softc;
+
+typedef int (*cfgread_handler)(struct passthru_softc *sc,
+    struct pci_devinst *pi, int coff, int bytes, uint32_t *rv);
+typedef int (*cfgwrite_handler)(struct passthru_softc *sc,
+    struct pci_devinst *pi, int coff, int bytes, uint32_t val);
+
 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 set_pcir_handler(struct passthru_softc *sc, int reg, int len,
+    cfgread_handler rhandler, cfgwrite_handler whandler);