Re: [PATCH v2 kvmtool] riscv: Move serial and rtc from IO port space to MMIO area.

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Wed, Feb 1, 2023 at 5:18 PM Alexandru Elisei
<alexandru.elisei@xxxxxxx> wrote:
>
> Hi,
>
> On Wed, Feb 01, 2023 at 05:04:36PM +0000, Rajnesh Kanwal wrote:
> > On Wed, Feb 1, 2023 at 4:35 PM
> > Andre Przywara <andre.przywara@xxxxxxxxxxxx> wrote:
> > >
> > > On Wed,  1 Feb 2023 16:01:37 +0000
> > > Rajnesh Kanwal <rkanwal@xxxxxxxxxxxx> wrote:
> > >
> > > Hi,
> > >
> > > > The default serial and rtc IO region overlaps with PCI IO bar
> > > > region leading bar 0 activation to fail. Moving these devices
> > > > to MMIO region similar to ARM.
> > > >
> > > > Given serial has been moved from 0x3f8 to 0x10000000, this
> > > > requires us to now pass earlycon=uart8250,mmio,0x10000000
> > > > from cmdline rather than earlycon=uart8250,mmio,0x3f8.
> > >
> > > Doesn't it work either way with just "earlycon"? At least on the ARM side
> > > it then finds the UART type and base address by following the DT's
> > > stdout-path property. This would not only make this more robust, but also
> > > more VMM agnostic.
>
> It might actually be better to have both ways of specifying the UART using
> earlycon in the commit message. Some might find it easier to do git log
> hw/serial.c to find the exact parameters than to follow the code and do the
> math.
>
> Spearking for myself, the commit message for the coresponding arm change
> contains the exact parameters (earlycon=uart,mmio,0x1000000) and that has
> been helpful when trying to figure out the address (for example, for
> kvm-unit-tests, you can configure the uart address at compile time, and
> that provides an earlycon which is usable even before the DTB is parsed).
>
> I think Andre was just trying to be helpful and point out that you don't
> need to full parameters to get earlycon working for a Linux guest.
>

Thanks Alex. I actually didn't know that we can just specify "earlycon" only.
Just in case I will mention both ways in the commit message to keep it clear.

Cheers,
Rajnesh

> Thanks,
> Alex
>
> > >
> >
> > Sorry I didn't know that. Thanks for pointing this out. Just tested this and it
> >  works fine with just "earlycon".
> >
> > $ ./lkvm-static run -c1 --console virtio -p "console=hvc1 earlycon
> > root=/dev/vda " -k ./Image -d rootfs.ext4
> > [    0.000000] earlycon: ns16550a0 at MMIO 0x0000000010000000 (options '')
> > [    0.000000] printk: bootconsole [ns16550a0] enabled
> >
> > I will update the commit message in the next version.
> >
> > Thanks,
> > Rajnesh
> >
> > > Also, Atish, Anup: can one of you please provide a Reviewed-by: or
> > > Tested-by: for this patch?
> > >
> > > Cheers,
> > > Andre
> > >
> > > >
> > > > Signed-off-by: Rajnesh Kanwal <rkanwal@xxxxxxxxxxxx>
> > > > ---
> > > > v2: Added further details in the commit message regarding the
> > > >     UART address change required in kernel cmdline parameter.
> > > >
> > > > v1: https://www.spinics.net/lists/kvm/msg301835.html
> > > >
> > > >  hw/rtc.c                     |  3 +++
> > > >  hw/serial.c                  |  4 ++++
> > > >  riscv/include/kvm/kvm-arch.h | 10 ++++++++--
> > > >  3 files changed, 15 insertions(+), 2 deletions(-)
> > > >
> > > > diff --git a/hw/rtc.c b/hw/rtc.c
> > > > index 9b8785a..da696e1 100644
> > > > --- a/hw/rtc.c
> > > > +++ b/hw/rtc.c
> > > > @@ -9,6 +9,9 @@
> > > >  #if defined(CONFIG_ARM) || defined(CONFIG_ARM64)
> > > >  #define RTC_BUS_TYPE         DEVICE_BUS_MMIO
> > > >  #define RTC_BASE_ADDRESS     ARM_RTC_MMIO_BASE
> > > > +#elif defined(CONFIG_RISCV)
> > > > +#define RTC_BUS_TYPE         DEVICE_BUS_MMIO
> > > > +#define RTC_BASE_ADDRESS     RISCV_RTC_MMIO_BASE
> > > >  #else
> > > >  /* PORT 0070-007F - CMOS RAM/RTC (REAL TIME CLOCK) */
> > > >  #define RTC_BUS_TYPE         DEVICE_BUS_IOPORT
> > > > diff --git a/hw/serial.c b/hw/serial.c
> > > > index 3d53362..b6263a0 100644
> > > > --- a/hw/serial.c
> > > > +++ b/hw/serial.c
> > > > @@ -17,6 +17,10 @@
> > > >  #define serial_iobase(nr)    (ARM_UART_MMIO_BASE + (nr) * 0x1000)
> > > >  #define serial_irq(nr)               (32 + (nr))
> > > >  #define SERIAL8250_BUS_TYPE  DEVICE_BUS_MMIO
> > > > +#elif defined(CONFIG_RISCV)
> > > > +#define serial_iobase(nr)    (RISCV_UART_MMIO_BASE + (nr) * 0x1000)
> > > > +#define serial_irq(nr)               (1 + (nr))
> > > > +#define SERIAL8250_BUS_TYPE  DEVICE_BUS_MMIO
> > > >  #else
> > > >  #define serial_iobase_0              (KVM_IOPORT_AREA + 0x3f8)
> > > >  #define serial_iobase_1              (KVM_IOPORT_AREA + 0x2f8)
> > > > diff --git a/riscv/include/kvm/kvm-arch.h b/riscv/include/kvm/kvm-arch.h
> > > > index 3f96d00..620c796 100644
> > > > --- a/riscv/include/kvm/kvm-arch.h
> > > > +++ b/riscv/include/kvm/kvm-arch.h
> > > > @@ -11,7 +11,7 @@
> > > >  #define RISCV_IOPORT         0x00000000ULL
> > > >  #define RISCV_IOPORT_SIZE    SZ_64K
> > > >  #define RISCV_IRQCHIP                0x08000000ULL
> > > > -#define RISCV_IRQCHIP_SIZE           SZ_128M
> > > > +#define RISCV_IRQCHIP_SIZE   SZ_128M
> > > >  #define RISCV_MMIO           0x10000000ULL
> > > >  #define RISCV_MMIO_SIZE              SZ_512M
> > > >  #define RISCV_PCI            0x30000000ULL
> > > > @@ -35,10 +35,16 @@
> > > >  #define RISCV_MAX_MEMORY(kvm)        RISCV_LOMAP_MAX_MEMORY
> > > >  #endif
> > > >
> > > > +#define RISCV_UART_MMIO_BASE RISCV_MMIO
> > > > +#define RISCV_UART_MMIO_SIZE 0x10000
> > > > +
> > > > +#define RISCV_RTC_MMIO_BASE  (RISCV_UART_MMIO_BASE + RISCV_UART_MMIO_SIZE)
> > > > +#define RISCV_RTC_MMIO_SIZE  0x10000
> > > > +
> > > >  #define KVM_IOPORT_AREA              RISCV_IOPORT
> > > >  #define KVM_PCI_CFG_AREA     RISCV_PCI
> > > >  #define KVM_PCI_MMIO_AREA    (KVM_PCI_CFG_AREA + RISCV_PCI_CFG_SIZE)
> > > > -#define KVM_VIRTIO_MMIO_AREA RISCV_MMIO
> > > > +#define KVM_VIRTIO_MMIO_AREA (RISCV_RTC_MMIO_BASE + RISCV_UART_MMIO_SIZE)
> > > >
> > > >  #define KVM_IOEVENTFD_HAS_PIO        0
> > > >
> > >



[Index of Archives]     [KVM ARM]     [KVM ia64]     [KVM ppc]     [Virtualization Tools]     [Spice Development]     [Libvirt]     [Libvirt Users]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite Questions]     [Linux Kernel]     [Linux SCSI]     [XFree86]

  Powered by Linux