lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Thu, 19 Jun 2014 16:42:43 +0200
From:	Paolo Bonzini <>
To:	Marcelo Tosatti <>,
	Andi Kleen <>
CC:	Andi Kleen <>,,,,,
Subject: Re: [PATCH 4/4] kvm: Implement PEBS virtualization

Il 10/06/2014 23:06, Marcelo Tosatti ha scritto:
> > BTW how about general PMU migration? As far as I can tell there
> > is no code to save/restore the state for that currently, right?
> Paolo wrote support for it, recently. Paolo?

Yes, on the KVM side all that is needed is to special case MSR reads and 
writes that have side effects, for example:

                 if (msr_info->host_initiated) {
                         pmu->global_status = data;
                         return 0;
                 break; /* RO MSR */
                 if (!(data & (pmu->global_ctrl_mask & ~(3ull<<62)))) {
                         if (!msr_info->host_initiated)
                                 pmu->global_status &= ~data;
                         pmu->global_ovf_ctrl = data;
                         return 0;

Right now this is only needed for writes.

Userspace then can read/write these MSRs, and add them to the migration 
stream.  QEMU has code for that.

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

Powered by blists - more mailing lists