RE: [Patch v5 1/4] Remove SMEP bit from CR4_RESERVED_BITS

2011-06-01 Thread Tian, Kevin
From: Ingo Molnar Sent: Monday, May 30, 2011 3:41 PM * Yang, Wei Y wei.y.y...@intel.com wrote: This patch removes SMEP bit from CR4_RESERVED_BITS. I'm wondering, what is the best-practice way for tools/kvm/ to set SMEP for the guest kernel automatically, even if the guest kernel

Re: [Patch v5 1/4] Remove SMEP bit from CR4_RESERVED_BITS

2011-06-01 Thread Ingo Molnar
* Tian, Kevin kevin.t...@intel.com wrote: From: Ingo Molnar Sent: Monday, May 30, 2011 3:41 PM * Yang, Wei Y wei.y.y...@intel.com wrote: This patch removes SMEP bit from CR4_RESERVED_BITS. I'm wondering, what is the best-practice way for tools/kvm/ to set SMEP for the

Re: [Patch v5 1/4] Remove SMEP bit from CR4_RESERVED_BITS

2011-05-30 Thread Ingo Molnar
* Yang, Wei Y wei.y.y...@intel.com wrote: This patch removes SMEP bit from CR4_RESERVED_BITS. I'm wondering, what is the best-practice way for tools/kvm/ to set SMEP for the guest kernel automatically, even if the guest kernel itsef has not requested SMEP? The portion i'm worried about are

Re: [Patch v5 1/4] Remove SMEP bit from CR4_RESERVED_BITS

2011-05-30 Thread Avi Kivity
On 05/30/2011 10:40 AM, Ingo Molnar wrote: * Yang, Wei Ywei.y.y...@intel.com wrote: This patch removes SMEP bit from CR4_RESERVED_BITS. I'm wondering, what is the best-practice way for tools/kvm/ to set SMEP for the guest kernel automatically, even if the guest kernel itsef has not

Re: [Patch v5 1/4] Remove SMEP bit from CR4_RESERVED_BITS

2011-05-30 Thread Ingo Molnar
* Avi Kivity a...@redhat.com wrote: On 05/30/2011 10:40 AM, Ingo Molnar wrote: * Yang, Wei Ywei.y.y...@intel.com wrote: This patch removes SMEP bit from CR4_RESERVED_BITS. I'm wondering, what is the best-practice way for tools/kvm/ to set SMEP for the guest kernel automatically, even

Re: [Patch v5 1/4] Remove SMEP bit from CR4_RESERVED_BITS

2011-05-30 Thread Avi Kivity
On 05/30/2011 11:05 AM, Ingo Molnar wrote: * Avi Kivitya...@redhat.com wrote: On 05/30/2011 10:40 AM, Ingo Molnar wrote: * Yang, Wei Ywei.y.y...@intel.com wrote: This patch removes SMEP bit from CR4_RESERVED_BITS. I'm wondering, what is the best-practice way for tools/kvm/

Re: [Patch v5 1/4] Remove SMEP bit from CR4_RESERVED_BITS

2011-05-30 Thread Ingo Molnar
* Avi Kivity a...@redhat.com wrote: Another option would be to try to set the SMEP bit *before* we enable paging. In theory this should not confuse a Linux guest - and while i have not tested it i *think* we let it survive in the saved_cr4_features shadow variable. That would make

Re: [Patch v5 1/4] Remove SMEP bit from CR4_RESERVED_BITS

2011-05-30 Thread Avi Kivity
On 05/30/2011 11:52 AM, Ingo Molnar wrote: * Avi Kivitya...@redhat.com wrote: Another option would be to try to set the SMEP bit *before* we enable paging. In theory this should not confuse a Linux guest - and while i have not tested it i *think* we let it survive in the

Re: [Patch v5 1/4] Remove SMEP bit from CR4_RESERVED_BITS

2011-05-30 Thread Ingo Molnar
* Avi Kivity a...@redhat.com wrote: On 05/30/2011 11:52 AM, Ingo Molnar wrote: * Avi Kivitya...@redhat.com wrote: Another option would be to try to set the SMEP bit *before* we enable paging. In theory this should not confuse a Linux guest - and while i have not tested it i

Re: [Patch v5 1/4] Remove SMEP bit from CR4_RESERVED_BITS

2011-05-30 Thread Avi Kivity
On 05/30/2011 11:57 AM, Ingo Molnar wrote: Oh, it wasn't clear to me that this was your preference as well - and i didnt see such a capability in this series [let me know if i blindly missed it] so i was wondering what the battle plan was fr that :-) There is no plan. If someone is

[Patch v5 1/4] Remove SMEP bit from CR4_RESERVED_BITS

2011-05-29 Thread Yang, Wei Y
This patch removes SMEP bit from CR4_RESERVED_BITS. Signed-off-by: Yang, Wei wei.y.y...@intel.com Signed-off-by: Shan, Haitao haitao.s...@intel.com Signed-off-by: Li, Xin xin...@intel.com --- arch/x86/include/asm/kvm_host.h |2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff