On Sat, Jul 23, 2022 at 7:22 PM Atish Patra <atishp@rivosinc.com> wrote:
>
> Since commit 40244040a7ac, multi-socket configuration with plic is
> broken as the hartid for second socket is calculated incorrectly.
> The hartid stored in addr_config already includes the offset
> for the base hartid for that socket. Adding it again would lead
> to segfault while creating the plic device for the virt machine.
> qdev_connect_gpio_out was also invoked with incorrect number of gpio
> lines.
>
> Fixes: 40244040a7ac (hw/intc: sifive_plic: Avoid overflowing the addr_config buffer)
>
> Signed-off-by: Atish Patra <atishp@rivosinc.com>
> ---
> hw/intc/sifive_plic.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/hw/intc/sifive_plic.c b/hw/intc/sifive_plic.c
> index 56d60e9ac935..fdac028a521f 100644
> --- a/hw/intc/sifive_plic.c
> +++ b/hw/intc/sifive_plic.c
> @@ -454,10 +454,10 @@ DeviceState *sifive_plic_create(hwaddr addr, char *hart_config,
>
> for (i = 0; i < plic->num_addrs; i++) {
> int cpu_num = plic->addr_config[i].hartid;
> - CPUState *cpu = qemu_get_cpu(hartid_base + cpu_num);
> + CPUState *cpu = qemu_get_cpu(cpu_num);
>
> if (plic->addr_config[i].mode == PLICMode_M) {
> - qdev_connect_gpio_out(dev, num_harts + cpu_num,
> + qdev_connect_gpio_out(dev, cpu_num,
Argh!
I was trying to get this ready to go into 7.1. I have been working on
updating my tests to catch this failure in the future as well.
While testing this change I noticed that it breaks the noMMU test case.
I think the correct fix is actually this (on top of your patch):
diff --git a/hw/intc/sifive_plic.c b/hw/intc/sifive_plic.c
index fdac028a52..af4ae3630e 100644
--- a/hw/intc/sifive_plic.c
+++ b/hw/intc/sifive_plic.c
@@ -457,7 +457,7 @@ DeviceState *sifive_plic_create(hwaddr addr, char
*hart_config,
CPUState *cpu = qemu_get_cpu(cpu_num);
if (plic->addr_config[i].mode == PLICMode_M) {
- qdev_connect_gpio_out(dev, cpu_num,
+ qdev_connect_gpio_out(dev, num_harts - plic->hartid_base + cpu_num,
qdev_get_gpio_in(DEVICE(cpu), IRQ_M_EXT));
}
if (plic->addr_config[i].mode == PLICMode_S) {
The idea is that we need to increment the second argument to
qdev_connect_gpio_out() for the PLICMode_M compared to the PLICMode_S
case.
This ensures that we do that correctly without breaking anything.
How does that look to you?
Ahh yes. That makes sense.
Tested the updated change on multi-socket as well.
Alistair
> qdev_get_gpio_in(DEVICE(cpu), IRQ_M_EXT));
> }
> if (plic->addr_config[i].mode == PLICMode_S) {
> --
> 2.25.1
>
>