Re: [PATCH 3/4] arm/arm64: KVM: Flush caches to memory on unmap

2015-01-13 Thread Marc Zyngier
On 13/01/15 13:47, Christoffer Dall wrote: > On Mon, Jan 12, 2015 at 09:13:52PM +0100, Christoffer Dall wrote: >> On Mon, Jan 12, 2015 at 11:15:34AM +, Marc Zyngier wrote: >>> On 11/01/15 12:30, Christoffer Dall wrote: On Fri, Jan 09, 2015 at 02:35:49PM +, Marc Zyngier wrote: > On

Re: [PATCH 3/4] arm/arm64: KVM: Flush caches to memory on unmap

2015-01-13 Thread Christoffer Dall
On Mon, Jan 12, 2015 at 09:13:52PM +0100, Christoffer Dall wrote: > On Mon, Jan 12, 2015 at 11:15:34AM +, Marc Zyngier wrote: > > On 11/01/15 12:30, Christoffer Dall wrote: > > > On Fri, Jan 09, 2015 at 02:35:49PM +, Marc Zyngier wrote: > > >> On 09/01/15 12:30, Christoffer Dall wrote: > >

Re: [PATCH 3/4] arm/arm64: KVM: Flush caches to memory on unmap

2015-01-12 Thread Christoffer Dall
On Mon, Jan 12, 2015 at 11:15:34AM +, Marc Zyngier wrote: > On 11/01/15 12:30, Christoffer Dall wrote: > > On Fri, Jan 09, 2015 at 02:35:49PM +, Marc Zyngier wrote: > >> On 09/01/15 12:30, Christoffer Dall wrote: > >>> On Thu, Jan 08, 2015 at 11:59:08AM +, Marc Zyngier wrote: > Let

Re: [PATCH 3/4] arm/arm64: KVM: Flush caches to memory on unmap

2015-01-12 Thread Marc Zyngier
On 11/01/15 12:30, Christoffer Dall wrote: > On Fri, Jan 09, 2015 at 02:35:49PM +, Marc Zyngier wrote: >> On 09/01/15 12:30, Christoffer Dall wrote: >>> On Thu, Jan 08, 2015 at 11:59:08AM +, Marc Zyngier wrote: Let's assume a guest has created an uncached mapping, and written to t

Re: [PATCH 3/4] arm/arm64: KVM: Flush caches to memory on unmap

2015-01-11 Thread Christoffer Dall
On Fri, Jan 09, 2015 at 02:35:49PM +, Marc Zyngier wrote: > On 09/01/15 12:30, Christoffer Dall wrote: > > On Thu, Jan 08, 2015 at 11:59:08AM +, Marc Zyngier wrote: > >> Let's assume a guest has created an uncached mapping, and written > >> to that page. Let's also assume that the host uses

Re: [PATCH 3/4] arm/arm64: KVM: Flush caches to memory on unmap

2015-01-09 Thread Marc Zyngier
On 09/01/15 12:30, Christoffer Dall wrote: > On Thu, Jan 08, 2015 at 11:59:08AM +, Marc Zyngier wrote: >> Let's assume a guest has created an uncached mapping, and written >> to that page. Let's also assume that the host uses a cache-coherent >> IO subsystem. Let's finally assume that the host

Re: [PATCH 3/4] arm/arm64: KVM: Flush caches to memory on unmap

2015-01-09 Thread Christoffer Dall
On Thu, Jan 08, 2015 at 11:59:08AM +, Marc Zyngier wrote: > Let's assume a guest has created an uncached mapping, and written > to that page. Let's also assume that the host uses a cache-coherent > IO subsystem. Let's finally assume that the host is under memory > pressure and starts to swap th

[PATCH 3/4] arm/arm64: KVM: Flush caches to memory on unmap

2015-01-08 Thread Marc Zyngier
Let's assume a guest has created an uncached mapping, and written to that page. Let's also assume that the host uses a cache-coherent IO subsystem. Let's finally assume that the host is under memory pressure and starts to swap things out. Before this "uncached" page is evicted, we need to make sur