qemu/include/hw/block/fdc.h

21 lines
524 B
C
Raw Normal View History

#ifndef HW_FDC_H
#define HW_FDC_H
#include "exec/hwaddr.h"
#include "qapi/qapi-types-block.h"
/* fdc.c */
#define MAX_FD 2
#define TYPE_ISA_FDC "isa-fdc"
fdc: Reject clash between -drive if=floppy and -global isa-fdc The floppy controller devices desugar their drive properties into floppy devices (since commit a92bd191a4 "fdc: Move qdev properties to FloppyDrive", v2.8.0). This involves some bad magic in fdctrl_connect_drives(), and exists for backward compatibility. The functions for boards to create floppy controller devices fdctrl_init_isa(), fdctrl_init_sysbus(), and sun4m_fdctrl_init() desugar -drive if=floppy to these floppy controller drive properties. If you use both -drive if=floppy (or its -fda / -fdb sugar) and -global isa-fdc for the same floppy device, -global silently loses the conflict, and both backends involved end up with the floppy device frontend attached, as demonstrated by iotest 172 (see commit before previous). This is wrong. Desugar -drive if=floppy straight to floppy devices instead, with helper fdctrl_init_drives(). The conflict now gets rejected cleanly: first, fdctrl_connect_drives() creates the floppy for the controller's property, then fdctrl_init_drives() attempts to create the floppy for -drive if=floppy, but fails because the unit is already in use. Output of iotest 172 changes in three ways: 1. The clash gets rejected. 2. In one test case, "info qtree" has the floppy devices swapped, and "info block" has their QOM paths swapped. This is because the floppy device for -fda now gets created after the one for -global isa-fdc.driveB. 3. The error message for -global floppy.drive=floppy0 changes. Before the patch, we set isa-fdc.driveA to -fda's block backend, then create the floppy device for it, then move the backend from isa-fdc.driveA to floppy.drive. Floppy creation fails when applying -global floppy.drive=floppy0, because floppy0 is still attached to isa-fdc. After the patch, we create the floppy for -fda, then set its drive property to floppy0. Now floppy creation succeeds, but setting the drive property fails, because -global already set it. Yes, this is exasperatingly complicated. Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20200622094227.1271650-5-armbru@redhat.com>
2020-06-22 12:42:15 +03:00
void isa_fdc_init_drives(ISADevice *fdc, DriveInfo **fds);
hw/block/fdc-sysbus: Always mark sysbus floppy controllers as not having DMA The sysbus floppy controllers (devices sysbus-fdc and sun-fdtwo) don't support DMA. The core floppy controller code expects this to be indicated by setting FDCtrl::dma_chann to -1. This used to be done in the device instance_init functions sysbus_fdc_initfn() and sun4m_fdc_initfn(), but in commit 1430759ec3e we refactored this code and accidentally lost the setting of dma_chann. For sysbus-fdc this has no ill effects because we were redundantly also setting dma_chann in fdctrl_init_sysbus(), but for sun-fdtwo this means that guests which try to enable DMA on the floppy controller will cause QEMU to crash because FDCtrl::dma is NULL. Set dma_chann to -1 in the common instance init, and remove the redundant code in fdctrl_init_sysbus() that is also setting it. There is a six-year-old FIXME comment in the jazz board code to the effect that in theory it should support doing DMA via a custom DMA controller. If anybody ever chooses to fix that they can do it by adding support for setting both FDCtrl::dma_chann and FDCtrl::dma. (A QOM link property 'dma-controller' on the sysbus device which can be set to an instance of IsaDmaClass is probably the way to go.) Fixes: 1430759ec3 ("hw/block/fdc: Extract SysBus floppy controllers to fdc-sysbus.c") Resolves: https://gitlab.com/qemu-project/qemu/-/issues/958 Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Reviewed-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk> Message-Id: <20220505101842.2757905-1-peter.maydell@linaro.org> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
2022-05-05 13:18:42 +03:00
void fdctrl_init_sysbus(qemu_irq irq, hwaddr mmio_base, DriveInfo **fds);
void sun4m_fdctrl_init(qemu_irq irq, hwaddr io_base,
DriveInfo **fds, qemu_irq *fdc_tc);
FloppyDriveType isa_fdc_get_drive_type(ISADevice *fdc, int i);
int cmos_get_fd_drive_type(FloppyDriveType fd0);
#endif