Re: [Xen-devel] [PATCH RFC v3 0/6] x86/idle: add halt poll support

On Mon, Nov 13, 2017 at 06:05:59PM +0800, Quan Xu wrote: > From: Yang Zhang > > Some latency-intensive workload have seen obviously performance > drop when running inside VM. The main reason is that the overhead > is amplified when running inside VM. The most cost I have

Re: [RFC PATCH v2 1/7] x86/paravirt: Add pv_idle_ops to paravirt ops

On Tue, Aug 29, 2017 at 11:46:35AM +, Yang Zhang wrote: > So far, pv_idle_ops.poll is the only ops for pv_idle. .poll is called in > idle path which will polling for a while before we enter the real idle > state. > > In virtualization, idle path includes several heavy operations > includes

Re: [PATCH v6 26/34] iommu/amd: Allow the AMD IOMMU to work with memory encryption

On June 15, 2017 11:33:22 AM EDT, Borislav Petkov wrote: >On Thu, Jun 15, 2017 at 09:59:45AM -0500, Tom Lendacky wrote: >> Actually the detection routine, amd_iommu_detect(), is part of the >> IOMMU_INIT_FINISH macro support which is called early through >mm_init() >> from

Re: [RFC PATCH v4 19/28] swiotlb: Add warnings for use of bounce buffers with SME

On Thu, Feb 16, 2017 at 09:46:19AM -0600, Tom Lendacky wrote: > Add warnings to let the user know when bounce buffers are being used for > DMA when SME is active. Since the bounce buffers are not in encrypted > memory, these notifications are to allow the user to determine some > appropriate

Re: [RFC PATCH v4 26/28] x86: Allow kexec to be used with SME

On Thu, Feb 16, 2017 at 09:47:55AM -0600, Tom Lendacky wrote: > Provide support so that kexec can be used to boot a kernel when SME is > enabled. Is the point of kexec and kdump to ehh, dump memory ? But if the rest of the memory is encrypted you won't get much, will you? Would it make sense to

Re: [PATCH 2/2] swiotlb: Add swiotlb=nobounce debug option

On Mon, Nov 07, 2016 at 07:57:11PM +0100, Geert Uytterhoeven wrote: > Hi Konrad, > > On Mon, Oct 31, 2016 at 6:52 PM, Konrad Rzeszutek Wilk > <konrad.w...@oracle.com> wrote: > > On Mon, Oct 31, 2016 at 04:45:04PM +0100, Geert Uytterhoeven wrote: > >> On architec

Re: [PATCH 1/2] swiotlb: Rate-limit printing when running out of SW-IOMMU space

On Mon, Oct 31, 2016 at 04:45:03PM +0100, Geert Uytterhoeven wrote: > If the system runs out of SW-IOMMU space, changes are high successive > requests will fail, too, flooding the kernel log. This is true > especially for streaming DMA, which is typically used repeatedly outside > the driver's

Re: [PATCH 2/2] swiotlb: Add swiotlb=nobounce debug option

On Mon, Oct 31, 2016 at 04:45:04PM +0100, Geert Uytterhoeven wrote: > On architectures like arm64, swiotlb is tied intimately to the core > architecture DMA support. In addition, ZONE_DMA cannot be disabled. > > To aid debugging and catch devices not supporting DMA to memory outside > the 32-bit

Re: [PATCH] arm64:swiotlb:Enable only when Input size through command line

On Fri, Jun 24, 2016 at 10:57:29AM +0800, Jisheng Zhang wrote: > Dear Konrad, > > On Thu, 23 Jun 2016 12:06:10 -0400 Konrad Rzeszutek Wilk wrote: > > > On June 23, 2016 10:30:34 AM EDT, Catalin Marinas <catalin.mari...@arm.com> > > wrote: > > >On Thu, Ju

Re: [PATCH] arm64:swiotlb:Enable only when Input size through command line

On June 23, 2016 10:30:34 AM EDT, Catalin Marinas wrote: >On Thu, Jun 23, 2016 at 05:43:40PM +0530, Manjeet Pawar wrote: >> From: Rohit Thapliyal >> >> swiotlb default size of 64M is too big as >> default value therefore it is made configurable

Re: [RFC v2] dma-mapping: Use unsigned long for dma_attrs

On Mon, May 30, 2016 at 01:54:06PM +0200, Krzysztof Kozlowski wrote: > The dma-mapping core and the implementations do not change the > DMA attributes passed by pointer. Thus the pointer can point to const > data. However the attributes do not have to be a bitfield. Instead > unsigned long will