Re: [Qemu-devel] Can VMX provide real mode support?
On 03/23/2012 07:58 PM, Luiz Capitulino wrote: On Wed, 21 Mar 2012 15:48:43 +0200 Avi Kivity a...@redhat.com wrote: On 03/21/2012 03:40 PM, Jan Kiszka wrote: On 2012-03-21 13:38, GaoYi wrote: Hi Jan, Since the newest Intel-VT supports the guest OS under the real mode, which was already supported in AMD-V, can the VMX in the latest KVM support that case? Yes, both with our without that unrestricted guest support (as Intel called it), real mode will generally work. Without that CPU feature, I think to recall that there were some limitations for big real mode, not sure. Yes, big real mode will not work without unrestricted guest. There was some work to emulate it (module option emulate_invalid_guest_state), but it is not complete. Can you provide a pointer for this? series? It's merged (look for emulate_invalid_guest_state in vmx.c), just incomplete. -- error compiling committee.c: too many arguments to function
Re: [Qemu-devel] Can VMX provide real mode support?
So if the VT already supports unrestricted guest, KVM can then runs such guest? 在 2012年3月25日 下午5:55，Avi Kivity a...@redhat.com写道： On 03/23/2012 07:58 PM, Luiz Capitulino wrote: On Wed, 21 Mar 2012 15:48:43 +0200 Avi Kivity a...@redhat.com wrote: On 03/21/2012 03:40 PM, Jan Kiszka wrote: On 2012-03-21 13:38, GaoYi wrote: Hi Jan, Since the newest Intel-VT supports the guest OS under the real mode, which was already supported in AMD-V, can the VMX in the latest KVM support that case? Yes, both with our without that unrestricted guest support (as Intel called it), real mode will generally work. Without that CPU feature, I think to recall that there were some limitations for big real mode, not sure. Yes, big real mode will not work without unrestricted guest. There was some work to emulate it (module option emulate_invalid_guest_state), but it is not complete. Can you provide a pointer for this? series? It's merged (look for emulate_invalid_guest_state in vmx.c), just incomplete. -- error compiling committee.c: too many arguments to function
Re: [Qemu-devel] Can VMX provide real mode support?
On Wed, 21 Mar 2012 15:48:43 +0200 Avi Kivity a...@redhat.com wrote: On 03/21/2012 03:40 PM, Jan Kiszka wrote: On 2012-03-21 13:38, GaoYi wrote: Hi Jan, Since the newest Intel-VT supports the guest OS under the real mode, which was already supported in AMD-V, can the VMX in the latest KVM support that case? Yes, both with our without that unrestricted guest support (as Intel called it), real mode will generally work. Without that CPU feature, I think to recall that there were some limitations for big real mode, not sure. Yes, big real mode will not work without unrestricted guest. There was some work to emulate it (module option emulate_invalid_guest_state), but it is not complete. Can you provide a pointer for this? series?
Re: [Qemu-devel] Can VMX provide real mode support?
On 2012-03-21 13:38, GaoYi wrote: Hi Jan, Since the newest Intel-VT supports the guest OS under the real mode, which was already supported in AMD-V, can the VMX in the latest KVM support that case? Yes, both with our without that unrestricted guest support (as Intel called it), real mode will generally work. Without that CPU feature, I think to recall that there were some limitations for big real mode, not sure. Jan -- Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux
Re: [Qemu-devel] Can VMX provide real mode support?
On 03/21/2012 03:40 PM, Jan Kiszka wrote: On 2012-03-21 13:38, GaoYi wrote: Hi Jan, Since the newest Intel-VT supports the guest OS under the real mode, which was already supported in AMD-V, can the VMX in the latest KVM support that case? Yes, both with our without that unrestricted guest support (as Intel called it), real mode will generally work. Without that CPU feature, I think to recall that there were some limitations for big real mode, not sure. Yes, big real mode will not work without unrestricted guest. There was some work to emulate it (module option emulate_invalid_guest_state), but it is not complete. -- error compiling committee.c: too many arguments to function
[Qemu-devel] Can VMX provide real mode support?
Hi Jan, Since the newest Intel-VT supports the guest OS under the real mode, which was already supported in AMD-V, can the VMX in the latest KVM support that case? Thanks, Yi
Re: [Qemu-devel] Can VMX provide real mode support?
Hi, Thanks for your prompt response. So if the CPU supports the real mode, the KVM can support the real mode guest and there is still work to be done for CPU without real mode support, namely software emulation? Again 在 2012年3月21日 下午9:48，Avi Kivity a...@redhat.com写道： On 03/21/2012 03:40 PM, Jan Kiszka wrote: On 2012-03-21 13:38, GaoYi wrote: Hi Jan, Since the newest Intel-VT supports the guest OS under the real mode, which was already supported in AMD-V, can the VMX in the latest KVM support that case? Yes, both with our without that unrestricted guest support (as Intel called it), real mode will generally work. Without that CPU feature, I think to recall that there were some limitations for big real mode, not sure. Yes, big real mode will not work without unrestricted guest. There was some work to emulate it (module option emulate_invalid_guest_state), but it is not complete. -- error compiling committee.c: too many arguments to function
