On Thu, May 23, 2024 at 08:52:35PM +0800, Aaron Lu wrote: > On Wed, May 22, 2024 at 08:34:13PM +0800, Aaron Lu wrote: > > > > I do not have Windows VM right now and will report back once I finished > > testing there. > > Tested with a Windows 10 VM and turnes out virtio pci devices always > use MSI no matter vIOMMU and bypass iommu are specified or not.
Just noticed another thing about Windows VM. If I install the VM without bypass iommu on: -machine q35,accel=kvm,kernel-irqchip=split \ -device intel-iommu \ -cdrom win10.iso Then the install went well and after installation, adding bypass iommu: -machine q35,accel=kvm,kernel-irqchip=split,default_bus_bypass_iommu=true \ -device intel-iommu \ -cdrom win10.iso doesn't change anything regarding PCI MSI functionality. But if I install the vm with bypass iommu on: -machine q35,accel=kvm,kernel-irqchip=split,default_bus_bypass_iommu=true \ -device intel-iommu \ -cdrom win10.iso then the install couldn't proceed and it appreas to me Windows couldn't read from the installation iso. Not sure what exactly happened but looks like something worth mentioning.
