Re: vmm(4): cpuid leaf 0x15 fixes clock speed problem in Linux guest [PATCH]

2020-12-07 Thread Chris Cappuccio
Pratik Vyas [m...@pd.io] wrote: > > This cpuid emulation bit was added during the time when using tsc was > the only way to get a precise clock and before pvclock was added [2]. This > also doesn't work on AMD machines (on at least mine). We could get rid > of this cpuid emulation. > If cpuid

Re: vmm(4): cpuid leaf 0x15 fixes clock speed problem in Linux guest [PATCH]

2020-12-05 Thread Pratik Vyas
* Jozef Hatala [2020-11-29 00:32:17 -0800]: On Sun, Nov 29, 2020 at 12:04:04AM -0800, I wrote: On Sun, Nov 29, 2020 at 06:36:17AM +, Mike wrote: > And what are you going to return for the other leaf nodes now that > you are claiming a CPUID level of 0x15, on CPUs that are less than >

Re: vmm(4): cpuid leaf 0x15 fixes clock speed problem in Linux guest [PATCH]

2020-11-29 Thread Jozef Hatala
On Sun, Nov 29, 2020 at 12:04:04AM -0800, I wrote: > On Sun, Nov 29, 2020 at 06:36:17AM +, Mike wrote: > > And what are you going to return for the other leaf nodes now that > > you are claiming a CPUID level of 0x15, on CPUs that are less than > > that? > > > > Eg, if your host supports

Re: vmm(4): cpuid leaf 0x15 fixes clock speed problem in Linux guest [PATCH]

2020-11-29 Thread Jozef Hatala
On Sun, Nov 29, 2020 at 06:36:17AM +, Mike wrote: > And what are you going to return for the other leaf nodes now that > you are claiming a CPUID level of 0x15, on CPUs that are less than > that? > > Eg, if your host supports level 0xb (11), what happens in your diff > if the guest VM

vmm(4): cpuid leaf 0x15 fixes clock speed problem in Linux guest [PATCH]

2020-11-28 Thread Jozef Hatala
Hello! On a host with Invariant TSC, vmm advertises to the guest support for cpuid leaves up to 0x15 (in the response to leaf 0x00), but when the guest asks for leaves higher than the host's cpuid level, vmm_handle_cpuid serves the response for host's highest cpuid leaf instead. A Linux guest