Date: Tue, 30 Nov 2021 23:56:07 +0000 From: bugzilla-noreply@freebsd.org To: virtualization@FreeBSD.org Subject: [Bug 260148] passthru stopped working Message-ID: <bug-260148-27103-owFzRoMCra@https.bugs.freebsd.org/bugzilla/> In-Reply-To: <bug-260148-27103@https.bugs.freebsd.org/bugzilla/> References: <bug-260148-27103@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=260148 --- Comment #4 from Bjoern A. Zeeb <bz@FreeBSD.org> --- okay, here's a fix:@@ -487,6 +487,7 @@ cfginitbar(struct vmctx *ctx, struct passthru_softc *sc) struct pci_bar_io bar; enum pcibar_type bartype; uint64_t base, size; + uint16_t cmd, orig_cmd; pi = sc->psc_pi; @@ -533,11 +534,22 @@ cfginitbar(struct vmctx *ctx, struct passthru_softc *sc) sc->psc_bar[i].addr = base; sc->psc_bar[i].lobits = 0; + orig_cmd = pci_get_cfgdata16(pi, PCIR_COMMAND); + /* Allocate the BAR in the guest I/O or MMIO space */ error = pci_emul_alloc_bar(pi, i, bartype, size); if (error) return (-1); + /* + * We may need this here and now to enable the BAR + * before pci_msix_table_bar() tries to mmap it as + * the kernel otherwise returns EBUSY from pci_bar_mmap(). + */ + cmd = pci_get_cfgdata16(pi, PCIR_COMMAND); + if (cmd != orig_cmd) + write_config(&sc->psc_sel, PCIR_COMMAND, 2, cmd); + /* Use same lobits as physical bar */ uint8_t lobits = read_config(&sc->psc_sel, PCIR_BAR(i), 0x01); if (bartype == PCIBAR_MEM32 || bartype == PCIBAR_MEM64) { This is very similar to what @jhb is doing in https://reviews.freebsd.org/D20623 for busmaster. Unfortunately the combined write at the end of cfginit() is too late these days. So we end up with several individual writes to PCIR_COMMAND and possibly yet-another-one not actually chaning anything anymore after all in cfginit(). -- You are receiving this mail because: You are the assignee for the bug.
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