From: Oleksandr Andrushchenko <[email protected]> Reset the command register when assigning a PCI device to a guest: according to the PCI spec the PCI_COMMAND register is typically all 0's after reset.
Signed-off-by: Oleksandr Andrushchenko <[email protected]> --- Since v5: - updated commit message Since v1: - do not write 0 to the command register, but respect host settings. --- xen/drivers/vpci/header.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/xen/drivers/vpci/header.c b/xen/drivers/vpci/header.c index 33d8c15ae6e8..407fa2fc4749 100644 --- a/xen/drivers/vpci/header.c +++ b/xen/drivers/vpci/header.c @@ -454,8 +454,7 @@ static void cmd_write(const struct pci_dev *pdev, unsigned int reg, pci_conf_write16(pdev->sbdf, reg, cmd); } -static void guest_cmd_write(const struct pci_dev *pdev, unsigned int reg, - uint32_t cmd, void *data) +static uint32_t emulate_cmd_reg(const struct pci_dev *pdev, uint32_t cmd) { /* TODO: Add proper emulation for all bits of the command register. */ @@ -467,7 +466,13 @@ static void guest_cmd_write(const struct pci_dev *pdev, unsigned int reg, } #endif - cmd_write(pdev, reg, cmd, data); + return cmd; +} + +static void guest_cmd_write(const struct pci_dev *pdev, unsigned int reg, + uint32_t cmd, void *data) +{ + cmd_write(pdev, reg, emulate_cmd_reg(pdev, cmd), data); } static void bar_write(const struct pci_dev *pdev, unsigned int reg, @@ -676,6 +681,10 @@ static int init_bars(struct pci_dev *pdev) return -EOPNOTSUPP; } + /* Reset the command register for the guest. */ + if ( !is_hwdom ) + pci_conf_write16(pdev->sbdf, PCI_COMMAND, emulate_cmd_reg(pdev, 0)); + /* Setup a handler for the command register. */ rc = vpci_add_register(pdev->vpci, vpci_hw_read16, is_hwdom ? cmd_write : guest_cmd_write, -- 2.25.1
