git: 2eb2079554f4 - main - bhyve: keep physical and virtual COMMAND reg in sync

From: Emmanuel Vadot <manu_at_FreeBSD.org>
Date: Mon, 22 Nov 2021 15:30:30 UTC
The branch main has been updated by manu:

URL: https://cgit.FreeBSD.org/src/commit/?id=2eb2079554f4d54c4283410b4ee1aca549b29616

commit 2eb2079554f4d54c4283410b4ee1aca549b29616
Author:     Corvin Köhne <CorvinK@beckhoff.com>
AuthorDate: 2021-11-22 15:26:03 +0000
Commit:     Emmanuel Vadot <manu@FreeBSD.org>
CommitDate: 2021-11-22 15:26:03 +0000

    bhyve: keep physical and virtual COMMAND reg in sync
    
    On startup all virtual BARs are registered.
    Additionally, the encoding bit in the virtual cmd register is set.
    After that, the passthru emulation overwrites the virtual cmd register with
    the physical one.
    This could lead to a mismatch between registered BARs and the encoding
    bits in the cmd register.
    Instead of writing the physical to the virtual cmd register,
    write the virtual to the physical cmd register to solve this issue.
    
    Reviewed by:      markj
    Differential Revision:  https://reviews.freebsd.org/D32687
    Sponsored by:   Beckhoff Automation GmbH & Co. KG
---
 usr.sbin/bhyve/pci_passthru.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/usr.sbin/bhyve/pci_passthru.c b/usr.sbin/bhyve/pci_passthru.c
index 29142749abb4..ed5d880ea8d1 100644
--- a/usr.sbin/bhyve/pci_passthru.c
+++ b/usr.sbin/bhyve/pci_passthru.c
@@ -593,8 +593,8 @@ cfginit(struct vmctx *ctx, struct pci_devinst *pi, int bus, int slot, int func)
 		goto done;
 	}
 
-	pci_set_cfgdata16(pi, PCIR_COMMAND, read_config(&sc->psc_sel,
-	    PCIR_COMMAND, 2));
+	write_config(&sc->psc_sel, PCIR_COMMAND, 2,
+	    pci_get_cfgdata16(pi, PCIR_COMMAND));
 
 	error = 0;				/* success */
 done: