6 ms·
Windows suffers from similar effects when Virtualization-Based Security is active.
by kookamamie 1y ago
Windows suffers from similar effects when Virtualization-Based Security is active.
- Avamander 1y agoAt the same time VBS is one of the biggest steps forward in terms of Windows kernel security. It's actually considered a proper security boundary.
- munchlax 1y agoFunny that they called it VBS. That's not something I'd easily associate with a step forward in security.
- transpute 1y agoHypervisor overhead should be low, https://www.howtogeek.com/does-windows-11-vbs-slow-pc-games/ https://www.howtogeek.com/does-windows-11-vbs-slow-pc-games/ What kind of workloads have noticeably lower performance with VBS?
- kookamamie 1y agoWe're working on HPC / graphics / computer-vision software and noticed a particularly nasty issue with VBS enabled just last week. Although, have to be mentioned it was on Win10 Pro.
- kachapopopow 1y agoThis most likely comes from IOMMU - disable it.
- jychang 1y agoThat’d break a lot of GPU setups
- kachapopopow 1y agoOnly if you want to virtualize it or have vms, for VBS it simply disables hardware pcie memory space isolation. (With IOMMU on, each pcie device gets an isolated memory buffer).
- jeroenhd 1y agoIt was measured to have a performance impact of up to 10%, with even higher numbers for the nth percentile lows: https://www.tomshardware.com/news/windows-vbs-harms-performance-rtx-4090 https://www.tomshardware.com/news/windows-vbs-harms-performa... Overhead should be minimal but something is preventing it from working as well as it theoretically should. AFAIK Microsoft has been improving VBS but I don't think it's completely fixed yet. BF6 requiring VBS (or at least "VBS capable" systems) will probably force games to find a way to deal with VBS as much as they can, but for older titles it's not always a bad idea to turn off VBS to get a less stuttery experience.
- UltraSane 1y agoVBS requires hyper-v to be enabled and it "owns" the CPU virtualization hardware so I can't use VMware workstation which is very annoying.
- davikr 1y agoSame. Have to disable VBS for VirtualBox, and it gets more and more obscure with each update because some features like Windows Hello force it back on.
- bpye 1y agoVMWare Workstation [0] (and I thought VirtualBox - though I can't find any official docs [1]) should be able to use the Hyper-V hypervisor via WHP. QEMU can also use WHP via --accel whpx. [0] - https://techcommunity.microsoft.com/blog/virtualization/vmware-workstation-and-hyper-v/1419928 https://techcommunity.microsoft.com/blog/virtualization/vmwa... [1] - https://www.impostr-labs.com/use-hyper-v-and-virtualbox-together-on-server-2019/ https://www.impostr-labs.com/use-hyper-v-and-virtualbox-toge...
- lenerdenator 1y agoAnything that runs on an ISA that has certain features has these effects, IIRC.