Re: [Xen-devel] [PATCH RFC] VMX: fix vmx_handle_eoi()

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 12.10.18 at 11:32, <JBeulich@xxxxxxxx> wrote:
> In commit 303066fdb1e ("VMX: fix interaction of APIC-V and Viridian
> emulation") I screwed up quite heavily: Instead of clearing SVI, RVI was
> cleared.

I was wrong here:

> @@ -2111,14 +2120,13 @@ static bool vmx_test_pir(const struct vc
>      return pi_test_pir(vec, &v->arch.hvm.vmx.pi_desc);
>  }
>  
> -static void vmx_handle_eoi(u8 vector)
> +static void vmx_handle_eoi(uint8_t vector, int isr)
>  {
> -    unsigned long status;
> +    u8 old_svi = set_svi(isr);
> +    static bool warned;
>  
> -    /* We need to clear the SVI field. */
> -    __vmread(GUEST_INTR_STATUS, &status);
> -    status &= VMX_GUEST_INTR_STATUS_SUBFIELD_BITMASK;

This indeed kept RVI, but wrongly masked off bits 16 and up. But
that's benign as long as those bits don#t have a meaning anyway.

The second aspect - ignoring ISR bits - still holds, so the change
itself is still needed afaict. Just the first paragraph of the
description would need to change.

Jan



_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-devel