Re: [PATCH v3] KVM: x86: Disable posted interrupts for odd IRQs

From: Sean Christopherson
Date: Thu Sep 05 2019 - 13:33:13 EST


On Thu, Sep 05, 2019 at 02:58:18PM +0200, Alexander Graf wrote:
> We can easily route hardware interrupts directly into VM context when
> they target the "Fixed" or "LowPriority" delivery modes.
>
> However, on modes such as "SMI" or "Init", we need to go via KVM code
> to actually put the vCPU into a different mode of operation, so we can
> not post the interrupt
>
> Add code in the VMX and SVM PI logic to explicitly refuse to establish
> posted mappings for advanced IRQ deliver modes. This reflects the logic
> in __apic_accept_irq() which also only ever passes Fixed and LowPriority
> interrupts as posted interrupts into the guest.
>
> This fixes a bug I have with code which configures real hardware to
> inject virtual SMIs into my guest.
>
> Signed-off-by: Alexander Graf <graf@xxxxxxxxxx>
>
> ---

Reviewed-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>