Messages in this thread | | | Date | Mon, 7 Oct 2019 18:26:36 +0200 | From | Borislav Petkov <> | Subject | Re: [PATCH v5 2/2] x86/jailhouse: Only enable platform UARTs if available |
| |
On Mon, Oct 07, 2019 at 02:38:19PM +0200, Ralf Ramsauer wrote: > ACPI tables aren't available if Linux runs as guest of the hypervisor > Jailhouse. This makes the 8250 driver probe for all platform UARTs as > it assumes that all platform are present in case of !ACPI. Jailhouse
I think you mean s/platform/UARTs/ here.
> will stop execution of Linux guest due to port access violation. > > So far, these access violations could be solved by tuning the > 8250.nr_uarts parameter but it has limitations: We can, e.g., only map
Another "We" you can get rid of.
> consecutive platform UARTs to Linux, and only in the sequence 0x3f8, > 0x2f8, 0x3e8, 0x2e8. > > Beginning from setup_data version 2, Jailhouse will place information of > available platform UARTs in setup_data. This allows for selective > activation of platform UARTs. > > This patch queries the setup_data version and activates only available
s/This patch queries/Query/
> UARTS. It comes with backward compatibility, and will still support > older setup_data versions. In this case, Linux falls back to the old > behaviour. > > Signed-off-by: Ralf Ramsauer <ralf.ramsauer@oth-regensburg.de> > --- > arch/x86/include/uapi/asm/bootparam.h | 3 + > arch/x86/kernel/jailhouse.c | 83 +++++++++++++++++++++++---- > 2 files changed, 74 insertions(+), 12 deletions(-)
...
> @@ -138,6 +147,53 @@ static int __init jailhouse_pci_arch_init(void) > return 0; > } > > +#ifdef CONFIG_SERIAL_8250 > +static bool jailhouse_uart_enabled(unsigned int uart_nr) > +{ > + return setup_data.v2.flags & BIT(uart_nr); > +} > + > +static void jailhouse_serial_fixup(int port, struct uart_port *up, > + u32 *capabilities) > +{ > + static const u16 pcuart_base[] = {0x3f8, 0x2f8, 0x3e8, 0x2e8}; > + unsigned int n; > + > + for (n = 0; n < ARRAY_SIZE(pcuart_base); n++) { > + if (pcuart_base[n] != up->iobase) > + continue; > + > + if (jailhouse_uart_enabled(n)) { > + pr_info("Enabling UART%u (port 0x%lx)\n", n, > + up->iobase); > + jailhouse_setup_irq(up->irq); > + } else { > + /* Deactivate UART if access isn't allowed */ > + up->iobase = 0; > + } > + break; > + } > +}
WARNING: vmlinux.o(.text+0x4fdb0): Section mismatch in reference from the function jailhouse_serial_fixup() to the variable .init.data:can_use_brk_pgt The function jailhouse_serial_fixup() references the variable __initdata can_use_brk_pgt. This is often because jailhouse_serial_fixup lacks a __initdata annotation or the annotation of can_use_brk_pgt is wrong.
-- Regards/Gruss, Boris.
https://people.kernel.org/tglx/notes-about-netiquette
| |