On 11/21/22 11:21, Roger Pau Monne wrote:
> When running as a PVH dom0 the ACPI MADT is crafted by Xen in order to
> report the correct numbers of vCPUs that dom0 has, so the host MADT is
> not provided to dom0. This creates issues when parsing the power and
> performance related data from ACPI dynamic tables, as the ACPI
> Processor UIDs found on the dynamic code are likely to not match the
> ones crafted by Xen in the dom0 MADT.
>
> Xen would rely on Linux having filled at least the power and
> performance related data of the vCPUs on the system, and would clone
> that information in order to setup the remaining pCPUs on the system
> if dom0 vCPUs < pCPUs. However when running as PVH dom0 it's likely
> that none of dom0 CPUs will have the power and performance data
> filled, and hence the Xen ACPI Processor driver needs to fetch that
> information by itself.
>
> In order to do so correctly, introduce a new helper to fetch the _CST
> data without taking into account the system capabilities from the
> CPUID output, as the capabilities reported to dom0 in CPUID might be
> different from the ones on the host.
>
>
Hi Roger,
First of all, thanks for doing the grunt work here to clear up the ACPI
situation.
A bit of background, I'm trying to get an AMD APU (CPUID 0x17 (23)) to
work properly
under Xen. It works fine otherwise but something is amiss under Xen.
Just to make sure that the patch is working as intended, what I found
when trying it out
is that the first 8 CPUs have C-States, but 0, 2, 4, 6, 8, 10, 12, 14
have P-States, out of
16 CPUs. Xen tells Linux that there are 8 CPUs since it's running with
nosmt.
Regards
- Josef
xen_acpi_processor: Max ACPI ID: 30
xen_acpi_processor: Uploading Xen processor PM info
xen_acpi_processor: ACPI CPU0 - C-states uploaded.
xen_acpi_processor: C1: ACPI HLT 1 uS
xen_acpi_processor: C2: ACPI IOPORT 0x414 18 uS
xen_acpi_processor: C3: ACPI IOPORT 0x415 350 uS
xen_acpi_processor: ACPI CPU0 - P-states uploaded.
xen_acpi_processor: *P0: 1700 MHz, 2071 mW, 0 uS
xen_acpi_processor: P1: 1600 MHz, 1520 mW, 0 uS
xen_acpi_processor: P2: 1400 MHz, 1277 mW, 0 uS
xen_acpi_processor: ACPI CPU1 - C-states uploaded.
xen_acpi_processor: C1: ACPI HLT 1 uS
xen_acpi_processor: C2: ACPI IOPORT 0x414 18 uS
xen_acpi_processor: C3: ACPI IOPORT 0x415 350 uS
xen_acpi_processor: ACPI CPU2 - C-states uploaded.
xen_acpi_processor: C1: ACPI HLT 1 uS
xen_acpi_processor: C2: ACPI IOPORT 0x414 18 uS
xen_acpi_processor: C3: ACPI IOPORT 0x415 350 uS
xen_acpi_processor: ACPI CPU2 - P-states uploaded.
xen_acpi_processor: *P0: 1700 MHz, 2071 mW, 0 uS
xen_acpi_processor: P1: 1600 MHz, 1520 mW, 0 uS
xen_acpi_processor: P2: 1400 MHz, 1277 mW, 0 uS
xen_acpi_processor: ACPI CPU3 - C-states uploaded.
xen_acpi_processor: C1: ACPI HLT 1 uS
xen_acpi_processor: C2: ACPI IOPORT 0x414 18 uS
xen_acpi_processor: C3: ACPI IOPORT 0x415 350 uS
xen_acpi_processor: ACPI CPU4 - C-states uploaded.
xen_acpi_processor: C1: ACPI HLT 1 uS
xen_acpi_processor: C2: ACPI IOPORT 0x414 18 uS
xen_acpi_processor: C3: ACPI IOPORT 0x415 350 uS
xen_acpi_processor: ACPI CPU4 - P-states uploaded.
xen_acpi_processor: *P0: 1700 MHz, 2071 mW, 0 uS
xen_acpi_processor: P1: 1600 MHz, 1520 mW, 0 uS
xen_acpi_processor: P2: 1400 MHz, 1277 mW, 0 uS
xen_acpi_processor: ACPI CPU5 - C-states uploaded.
xen_acpi_processor: C1: ACPI HLT 1 uS
xen_acpi_processor: C2: ACPI IOPORT 0x414 18 uS
xen_acpi_processor: C3: ACPI IOPORT 0x415 350 uS
xen_acpi_processor: ACPI CPU6 - C-states uploaded.
xen_acpi_processor: C1: ACPI HLT 1 uS
xen_acpi_processor: C2: ACPI IOPORT 0x414 18 uS
xen_acpi_processor: C3: ACPI IOPORT 0x415 350 uS
xen_acpi_processor: ACPI CPU6 - P-states uploaded.
xen_acpi_processor: *P0: 1700 MHz, 2071 mW, 0 uS
xen_acpi_processor: P1: 1600 MHz, 1520 mW, 0 uS
xen_acpi_processor: P2: 1400 MHz, 1277 mW, 0 uS
xen_acpi_processor: ACPI CPU7 - C-states uploaded.
xen_acpi_processor: C1: ACPI HLT 1 uS
xen_acpi_processor: C2: ACPI IOPORT 0x414 18 uS
xen_acpi_processor: C3: ACPI IOPORT 0x415 350 uS
xen_acpi_processor: ACPI CPU0 w/ PBLK:0x0
xen_acpi_processor: ACPI CPU0 w/ PST:coord_type = 254 domain = 0
xen_acpi_processor: CPU with ACPI ID 1 is unavailable
xen_acpi_processor: ACPI CPU2 w/ PBLK:0x0
xen_acpi_processor: ACPI CPU2 w/ PST:coord_type = 254 domain = 1
xen_acpi_processor: CPU with ACPI ID 3 is unavailable
xen_acpi_processor: ACPI CPU4 w/ PBLK:0x0
xen_acpi_processor: ACPI CPU4 w/ PST:coord_type = 254 domain = 2
xen_acpi_processor: CPU with ACPI ID 5 is unavailable
xen_acpi_processor: ACPI CPU6 w/ PBLK:0x0
xen_acpi_processor: ACPI CPU6 w/ PST:coord_type = 254 domain = 3
xen_acpi_processor: CPU with ACPI ID 7 is unavailable
xen_acpi_processor: ACPI CPU8 w/ PBLK:0x0
xen_acpi_processor: ACPI CPU8 w/ PST:coord_type = 254 domain = 4
xen_acpi_processor: CPU with ACPI ID 9 is unavailable
xen_acpi_processor: ACPI CPU10 w/ PBLK:0x0
xen_acpi_processor: ACPI CPU10 w/ PST:coord_type = 254 domain = 5
xen_acpi_processor: CPU with ACPI ID 11 is unavailable
xen_acpi_processor: ACPI CPU12 w/ PBLK:0x0
xen_acpi_processor: ACPI CPU12 w/ PST:coord_type = 254 domain = 6
xen_acpi_processor: CPU with ACPI ID 13 is unavailable
xen_acpi_processor: ACPI CPU14 w/ PBLK:0x0
xen_acpi_processor: ACPI CPU14 w/ PST:coord_type = 254 domain = 7
xen_acpi_processor: CPU with ACPI ID 15 is unavailable
xen_acpi_processor: ACPI CPU8 - P-states uploaded.
xen_acpi_processor: *P0: 1700 MHz, 2071 mW, 0 uS
xen_acpi_processor: P1: 1600 MHz, 1520 mW, 0 uS
xen_acpi_processor: P2: 1400 MHz, 1277 mW, 0 uS
xen_acpi_processor: ACPI CPU10 - P-states uploaded.
xen_acpi_processor: *P0: 1700 MHz, 2071 mW, 0 uS
xen_acpi_processor: P1: 1600 MHz, 1520 mW, 0 uS
xen_acpi_processor: P2: 1400 MHz, 1277 mW, 0 uS
xen_acpi_processor: ACPI CPU12 - P-states uploaded.
xen_acpi_processor: *P0: 1700 MHz, 2071 mW, 0 uS
xen_acpi_processor: P1: 1600 MHz, 1520 mW, 0 uS
xen_acpi_processor: P2: 1400 MHz, 1277 mW, 0 uS
xen_acpi_processor: ACPI CPU14 - P-states uploaded.
xen_acpi_processor: *P0: 1700 MHz, 2071 mW, 0 uS
xen_acpi_processor: P1: 1600 MHz, 1520 mW, 0 uS
xen_acpi_processor: P2: 1400 MHz, 1277 mW, 0 uS
As a bonus, here are the previous debug output on the same machine.
xen_acpi_processor: Max ACPI ID: 30
xen_acpi_processor: Uploading Xen processor PM info
xen_acpi_processor: ACPI CPU0 - C-states uploaded.
xen_acpi_processor: C1: ACPI HLT 1 uS
xen_acpi_processor: C2: ACPI IOPORT 0x414 18 uS
xen_acpi_processor: C3: ACPI IOPORT 0x415 350 uS
xen_acpi_processor: ACPI CPU0 - P-states uploaded.
xen_acpi_processor: *P0: 1700 MHz, 2071 mW, 0 uS
xen_acpi_processor: P1: 1600 MHz, 1520 mW, 0 uS
xen_acpi_processor: P2: 1400 MHz, 1277 mW, 0 uS
xen_acpi_processor: ACPI CPU1 - C-states uploaded.
xen_acpi_processor: C1: ACPI HLT 1 uS
xen_acpi_processor: C2: ACPI IOPORT 0x414 18 uS
xen_acpi_processor: C3: ACPI IOPORT 0x415 350 uS
xen_acpi_processor: ACPI CPU2 - C-states uploaded.
xen_acpi_processor: C1: ACPI HLT 1 uS
xen_acpi_processor: C2: ACPI IOPORT 0x414 18 uS
xen_acpi_processor: C3: ACPI IOPORT 0x415 350 uS
xen_acpi_processor: ACPI CPU2 - P-states uploaded.
xen_acpi_processor: *P0: 1700 MHz, 2071 mW, 0 uS
xen_acpi_processor: P1: 1600 MHz, 1520 mW, 0 uS
xen_acpi_processor: P2: 1400 MHz, 1277 mW, 0 uS
xen_acpi_processor: ACPI CPU3 - C-states uploaded.
xen_acpi_processor: C1: ACPI HLT 1 uS
xen_acpi_processor: C2: ACPI IOPORT 0x414 18 uS
xen_acpi_processor: C3: ACPI IOPORT 0x415 350 uS
xen_acpi_processor: ACPI CPU4 - C-states uploaded.
xen_acpi_processor: C1: ACPI HLT 1 uS
xen_acpi_processor: C2: ACPI IOPORT 0x414 18 uS
xen_acpi_processor: C3: ACPI IOPORT 0x415 350 uS
xen_acpi_processor: ACPI CPU4 - P-states uploaded.
xen_acpi_processor: *P0: 1700 MHz, 2071 mW, 0 uS
xen_acpi_processor: P1: 1600 MHz, 1520 mW, 0 uS
xen_acpi_processor: P2: 1400 MHz, 1277 mW, 0 uS
xen_acpi_processor: ACPI CPU5 - C-states uploaded.
xen_acpi_processor: C1: ACPI HLT 1 uS
xen_acpi_processor: C2: ACPI IOPORT 0x414 18 uS
xen_acpi_processor: C3: ACPI IOPORT 0x415 350 uS
xen_acpi_processor: ACPI CPU6 - C-states uploaded.
xen_acpi_processor: C1: ACPI HLT 1 uS
xen_acpi_processor: C2: ACPI IOPORT 0x414 18 uS
xen_acpi_processor: C3: ACPI IOPORT 0x415 350 uS
xen_acpi_processor: ACPI CPU6 - P-states uploaded.
xen_acpi_processor: *P0: 1700 MHz, 2071 mW, 0 uS
xen_acpi_processor: P1: 1600 MHz, 1520 mW, 0 uS
xen_acpi_processor: P2: 1400 MHz, 1277 mW, 0 uS
xen_acpi_processor: ACPI CPU7 - C-states uploaded.
xen_acpi_processor: C1: ACPI HLT 1 uS
xen_acpi_processor: C2: ACPI IOPORT 0x414 18 uS
xen_acpi_processor: C3: ACPI IOPORT 0x415 350 uS
xen_acpi_processor: ACPI CPU0 w/ PBLK:0x0
xen_acpi_processor: ACPI CPU0 w/ PST:coord_type = 254 domain = 0
xen_acpi_processor: ACPI CPU1 w/ PBLK:0x0
xen_acpi_processor: ACPI CPU1 w/ PST:coord_type = 254 domain = 0
xen_acpi_processor: ACPI CPU2 w/ PBLK:0x0
xen_acpi_processor: ACPI CPU2 w/ PST:coord_type = 254 domain = 1
xen_acpi_processor: ACPI CPU3 w/ PBLK:0x0
xen_acpi_processor: ACPI CPU3 w/ PST:coord_type = 254 domain = 1
xen_acpi_processor: ACPI CPU4 w/ PBLK:0x0
xen_acpi_processor: ACPI CPU4 w/ PST:coord_type = 254 domain = 2
xen_acpi_processor: ACPI CPU5 w/ PBLK:0x0
xen_acpi_processor: ACPI CPU5 w/ PST:coord_type = 254 domain = 2
xen_acpi_processor: ACPI CPU6 w/ PBLK:0x0
xen_acpi_processor: ACPI CPU6 w/ PST:coord_type = 254 domain = 3
xen_acpi_processor: ACPI CPU7 w/ PBLK:0x0
xen_acpi_processor: ACPI CPU7 w/ PST:coord_type = 254 domain = 3
xen_acpi_processor: ACPI CPU8 w/ PBLK:0x0
xen_acpi_processor: ACPI CPU8 w/ PST:coord_type = 254 domain = 4
xen_acpi_processor: ACPI CPU9 w/ PBLK:0x0
xen_acpi_processor: ACPI CPU9 w/ PST:coord_type = 254 domain = 4
xen_acpi_processor: ACPI CPU10 w/ PBLK:0x0
xen_acpi_processor: ACPI CPU10 w/ PST:coord_type = 254 domain = 5
xen_acpi_processor: ACPI CPU11 w/ PBLK:0x0
xen_acpi_processor: ACPI CPU11 w/ PST:coord_type = 254 domain = 5
xen_acpi_processor: ACPI CPU12 w/ PBLK:0x0
xen_acpi_processor: ACPI CPU12 w/ PST:coord_type = 254 domain = 6
xen_acpi_processor: ACPI CPU13 w/ PBLK:0x0
xen_acpi_processor: ACPI CPU13 w/ PST:coord_type = 254 domain = 6
xen_acpi_processor: ACPI CPU14 w/ PBLK:0x0
xen_acpi_processor: ACPI CPU14 w/ PST:coord_type = 254 domain = 7
xen_acpi_processor: ACPI CPU15 w/ PBLK:0x0
xen_acpi_processor: ACPI CPU15 w/ PST:coord_type = 254 domain = 7
xen_acpi_processor: ACPI CPU8 - P-states uploaded.
xen_acpi_processor: *P0: 1700 MHz, 2071 mW, 0 uS
xen_acpi_processor: P1: 1600 MHz, 1520 mW, 0 uS
xen_acpi_processor: P2: 1400 MHz, 1277 mW, 0 uS
xen_acpi_processor: ACPI CPU10 - P-states uploaded.
xen_acpi_processor: *P0: 1700 MHz, 2071 mW, 0 uS
xen_acpi_processor: P1: 1600 MHz, 1520 mW, 0 uS
xen_acpi_processor: P2: 1400 MHz, 1277 mW, 0 uS
xen_acpi_processor: ACPI CPU12 - P-states uploaded.
xen_acpi_processor: *P0: 1700 MHz, 2071 mW, 0 uS
xen_acpi_processor: P1: 1600 MHz, 1520 mW, 0 uS
xen_acpi_processor: P2: 1400 MHz, 1277 mW, 0 uS
xen_acpi_processor: ACPI CPU14 - P-states uploaded.
xen_acpi_processor: *P0: 1700 MHz, 2071 mW, 0 uS
xen_acpi_processor: P1: 1600 MHz, 1520 mW, 0 uS
xen_acpi_processor: P2: 1400 MHz, 1277 mW, 0 uS
On Mon, Jan 30, 2023 at 10:10:05AM +0100, Josef Johansson wrote:
>
> On 11/21/22 11:21, Roger Pau Monne wrote:
> > When running as a PVH dom0 the ACPI MADT is crafted by Xen in order to
> > report the correct numbers of vCPUs that dom0 has, so the host MADT is
> > not provided to dom0. This creates issues when parsing the power and
> > performance related data from ACPI dynamic tables, as the ACPI
> > Processor UIDs found on the dynamic code are likely to not match the
> > ones crafted by Xen in the dom0 MADT.
> >
> > Xen would rely on Linux having filled at least the power and
> > performance related data of the vCPUs on the system, and would clone
> > that information in order to setup the remaining pCPUs on the system
> > if dom0 vCPUs < pCPUs. However when running as PVH dom0 it's likely
> > that none of dom0 CPUs will have the power and performance data
> > filled, and hence the Xen ACPI Processor driver needs to fetch that
> > information by itself.
> >
> > In order to do so correctly, introduce a new helper to fetch the _CST
> > data without taking into account the system capabilities from the
> > CPUID output, as the capabilities reported to dom0 in CPUID might be
> > different from the ones on the host.
> >
> >
>
> Hi Roger,
>
> First of all, thanks for doing the grunt work here to clear up the ACPI
> situation.
>
> A bit of background, I'm trying to get an AMD APU (CPUID 0x17 (23)) to work
> properly
> under Xen. It works fine otherwise but something is amiss under Xen.
Hello,
Sorry for the delay, I've been on paternity leave and just caching up
on emails.
> Just to make sure that the patch is working as intended, what I found when
> trying it out
> is that the first 8 CPUs have C-States, but 0, 2, 4, 6, 8, 10, 12, 14 have
> P-States, out of
> 16 CPUs. Xen tells Linux that there are 8 CPUs since it's running with
> nosmt.
>
> Regards
> - Josef
>
> xen_acpi_processor: Max ACPI ID: 30
> xen_acpi_processor: Uploading Xen processor PM info
> xen_acpi_processor: ACPI CPU0 - C-states uploaded.
> xen_acpi_processor: C1: ACPI HLT 1 uS
> xen_acpi_processor: C2: ACPI IOPORT 0x414 18 uS
> xen_acpi_processor: C3: ACPI IOPORT 0x415 350 uS
> xen_acpi_processor: ACPI CPU0 - P-states uploaded.
> xen_acpi_processor: *P0: 1700 MHz, 2071 mW, 0 uS
> xen_acpi_processor: P1: 1600 MHz, 1520 mW, 0 uS
> xen_acpi_processor: P2: 1400 MHz, 1277 mW, 0 uS
> xen_acpi_processor: ACPI CPU1 - C-states uploaded.
> xen_acpi_processor: C1: ACPI HLT 1 uS
> xen_acpi_processor: C2: ACPI IOPORT 0x414 18 uS
> xen_acpi_processor: C3: ACPI IOPORT 0x415 350 uS
> xen_acpi_processor: ACPI CPU2 - C-states uploaded.
> xen_acpi_processor: C1: ACPI HLT 1 uS
> xen_acpi_processor: C2: ACPI IOPORT 0x414 18 uS
> xen_acpi_processor: C3: ACPI IOPORT 0x415 350 uS
> xen_acpi_processor: ACPI CPU2 - P-states uploaded.
> xen_acpi_processor: *P0: 1700 MHz, 2071 mW, 0 uS
> xen_acpi_processor: P1: 1600 MHz, 1520 mW, 0 uS
> xen_acpi_processor: P2: 1400 MHz, 1277 mW, 0 uS
> xen_acpi_processor: ACPI CPU3 - C-states uploaded.
> xen_acpi_processor: C1: ACPI HLT 1 uS
> xen_acpi_processor: C2: ACPI IOPORT 0x414 18 uS
> xen_acpi_processor: C3: ACPI IOPORT 0x415 350 uS
> xen_acpi_processor: ACPI CPU4 - C-states uploaded.
> xen_acpi_processor: C1: ACPI HLT 1 uS
> xen_acpi_processor: C2: ACPI IOPORT 0x414 18 uS
> xen_acpi_processor: C3: ACPI IOPORT 0x415 350 uS
> xen_acpi_processor: ACPI CPU4 - P-states uploaded.
> xen_acpi_processor: *P0: 1700 MHz, 2071 mW, 0 uS
> xen_acpi_processor: P1: 1600 MHz, 1520 mW, 0 uS
> xen_acpi_processor: P2: 1400 MHz, 1277 mW, 0 uS
> xen_acpi_processor: ACPI CPU5 - C-states uploaded.
> xen_acpi_processor: C1: ACPI HLT 1 uS
> xen_acpi_processor: C2: ACPI IOPORT 0x414 18 uS
> xen_acpi_processor: C3: ACPI IOPORT 0x415 350 uS
> xen_acpi_processor: ACPI CPU6 - C-states uploaded.
> xen_acpi_processor: C1: ACPI HLT 1 uS
> xen_acpi_processor: C2: ACPI IOPORT 0x414 18 uS
> xen_acpi_processor: C3: ACPI IOPORT 0x415 350 uS
> xen_acpi_processor: ACPI CPU6 - P-states uploaded.
> xen_acpi_processor: *P0: 1700 MHz, 2071 mW, 0 uS
> xen_acpi_processor: P1: 1600 MHz, 1520 mW, 0 uS
> xen_acpi_processor: P2: 1400 MHz, 1277 mW, 0 uS
> xen_acpi_processor: ACPI CPU7 - C-states uploaded.
> xen_acpi_processor: C1: ACPI HLT 1 uS
> xen_acpi_processor: C2: ACPI IOPORT 0x414 18 uS
> xen_acpi_processor: C3: ACPI IOPORT 0x415 350 uS
> xen_acpi_processor: ACPI CPU0 w/ PBLK:0x0
> xen_acpi_processor: ACPI CPU0 w/ PST:coord_type = 254 domain = 0
> xen_acpi_processor: CPU with ACPI ID 1 is unavailable
Hm, that's weird, do you think you could check why it reports the CPU
is unavailable?
Overall I don't like the situation of the ACPI handling when running
as dom0. It's fragile to rely on the data for dom0 CPUs to be
filled by the system (by adding some band aids here and there so that
the PV vCPUs are matched against the MADT objects) and then cloning
the data for any physical CPU exceeding the number of dom0 virtual
CPUs.
IMO it would be much better to just do the handling of ACPI processor
objects in a Xen specific driver (preventing the native driver from
attaching) in order to fetch the data and upload it to Xen. This is
what I've attempted to do on FreeBSD, and resulted in a cleaner
implementation:
https://cgit.freebsd.org/src/tree/sys/dev/xen/cpu/xen_acpi_cpu.c
I however don't have time to do this right now for Linux.
> xen_acpi_processor: ACPI CPU2 w/ PBLK:0x0
> xen_acpi_processor: ACPI CPU2 w/ PST:coord_type = 254 domain = 1
> xen_acpi_processor: CPU with ACPI ID 3 is unavailable
> xen_acpi_processor: ACPI CPU4 w/ PBLK:0x0
> xen_acpi_processor: ACPI CPU4 w/ PST:coord_type = 254 domain = 2
> xen_acpi_processor: CPU with ACPI ID 5 is unavailable
> xen_acpi_processor: ACPI CPU6 w/ PBLK:0x0
> xen_acpi_processor: ACPI CPU6 w/ PST:coord_type = 254 domain = 3
> xen_acpi_processor: CPU with ACPI ID 7 is unavailable
> xen_acpi_processor: ACPI CPU8 w/ PBLK:0x0
> xen_acpi_processor: ACPI CPU8 w/ PST:coord_type = 254 domain = 4
> xen_acpi_processor: CPU with ACPI ID 9 is unavailable
> xen_acpi_processor: ACPI CPU10 w/ PBLK:0x0
> xen_acpi_processor: ACPI CPU10 w/ PST:coord_type = 254 domain = 5
> xen_acpi_processor: CPU with ACPI ID 11 is unavailable
> xen_acpi_processor: ACPI CPU12 w/ PBLK:0x0
> xen_acpi_processor: ACPI CPU12 w/ PST:coord_type = 254 domain = 6
> xen_acpi_processor: CPU with ACPI ID 13 is unavailable
> xen_acpi_processor: ACPI CPU14 w/ PBLK:0x0
> xen_acpi_processor: ACPI CPU14 w/ PST:coord_type = 254 domain = 7
> xen_acpi_processor: CPU with ACPI ID 15 is unavailable
> xen_acpi_processor: ACPI CPU8 - P-states uploaded.
> xen_acpi_processor: *P0: 1700 MHz, 2071 mW, 0 uS
> xen_acpi_processor: P1: 1600 MHz, 1520 mW, 0 uS
> xen_acpi_processor: P2: 1400 MHz, 1277 mW, 0 uS
> xen_acpi_processor: ACPI CPU10 - P-states uploaded.
> xen_acpi_processor: *P0: 1700 MHz, 2071 mW, 0 uS
> xen_acpi_processor: P1: 1600 MHz, 1520 mW, 0 uS
> xen_acpi_processor: P2: 1400 MHz, 1277 mW, 0 uS
> xen_acpi_processor: ACPI CPU12 - P-states uploaded.
> xen_acpi_processor: *P0: 1700 MHz, 2071 mW, 0 uS
> xen_acpi_processor: P1: 1600 MHz, 1520 mW, 0 uS
> xen_acpi_processor: P2: 1400 MHz, 1277 mW, 0 uS
> xen_acpi_processor: ACPI CPU14 - P-states uploaded.
> xen_acpi_processor: *P0: 1700 MHz, 2071 mW, 0 uS
> xen_acpi_processor: P1: 1600 MHz, 1520 mW, 0 uS
> xen_acpi_processor: P2: 1400 MHz, 1277 mW, 0 uS
>
> As a bonus, here are the previous debug output on the same machine.
I think the output below is with dom0 running as plain PV rather than
PVH?
Thanks, Roger.
On 3/15/23 12:39, Roger Pau Monné wrote:
> On Mon, Jan 30, 2023 at 10:10:05AM +0100, Josef Johansson wrote:
>> On 11/21/22 11:21, Roger Pau Monne wrote:
>>> When running as a PVH dom0 the ACPI MADT is crafted by Xen in order to
>>> report the correct numbers of vCPUs that dom0 has, so the host MADT is
>>> not provided to dom0. This creates issues when parsing the power and
>>> performance related data from ACPI dynamic tables, as the ACPI
>>> Processor UIDs found on the dynamic code are likely to not match the
>>> ones crafted by Xen in the dom0 MADT.
>>>
>>> Xen would rely on Linux having filled at least the power and
>>> performance related data of the vCPUs on the system, and would clone
>>> that information in order to setup the remaining pCPUs on the system
>>> if dom0 vCPUs < pCPUs. However when running as PVH dom0 it's likely
>>> that none of dom0 CPUs will have the power and performance data
>>> filled, and hence the Xen ACPI Processor driver needs to fetch that
>>> information by itself.
>>>
>>> In order to do so correctly, introduce a new helper to fetch the _CST
>>> data without taking into account the system capabilities from the
>>> CPUID output, as the capabilities reported to dom0 in CPUID might be
>>> different from the ones on the host.
>>>
>>>
>> Hi Roger,
>>
>> First of all, thanks for doing the grunt work here to clear up the ACPI
>> situation.
>>
>> A bit of background, I'm trying to get an AMD APU (CPUID 0x17 (23)) to work
>> properly
>> under Xen. It works fine otherwise but something is amiss under Xen.
> Hello,
>
> Sorry for the delay, I've been on paternity leave and just caching up
> on emails.
Hi Roger,
Congratulations! I hope you had time to really connect. It's the most
important thing we can do here in life.
I came into this to understand each and every error in my boot-log, it
turns out that the latest
kernel+xen+firmware fixes suspend/resume for me, thus is this not
related. But as I pointed out,
the output does not make any sense (nor yours nor the upstream). I
should check the debug
output with suspend working fine now to see if there are any changes,
that would be quite
interesting.
Also, I should mention that your patch broke some things on my system
and made it
unstable. I don't remember exactly and I know you said that this is more
of a PoC. Just a
heads up.
>> Just to make sure that the patch is working as intended, what I found when
>> trying it out
>> is that the first 8 CPUs have C-States, but 0, 2, 4, 6, 8, 10, 12, 14 have
>> P-States, out of
>> 16 CPUs. Xen tells Linux that there are 8 CPUs since it's running with
>> nosmt.
>>
>> Regards
>> - Josef
>>
>> xen_acpi_processor: Max ACPI ID: 30
>> xen_acpi_processor: Uploading Xen processor PM info
>> xen_acpi_processor: ACPI CPU0 - C-states uploaded.
>> xen_acpi_processor: C1: ACPI HLT 1 uS
>> xen_acpi_processor: C2: ACPI IOPORT 0x414 18 uS
>> xen_acpi_processor: C3: ACPI IOPORT 0x415 350 uS
>> xen_acpi_processor: ACPI CPU0 - P-states uploaded.
>> xen_acpi_processor: *P0: 1700 MHz, 2071 mW, 0 uS
>> xen_acpi_processor: P1: 1600 MHz, 1520 mW, 0 uS
>> xen_acpi_processor: P2: 1400 MHz, 1277 mW, 0 uS
>> xen_acpi_processor: ACPI CPU1 - C-states uploaded.
>> xen_acpi_processor: C1: ACPI HLT 1 uS
>> xen_acpi_processor: C2: ACPI IOPORT 0x414 18 uS
>> xen_acpi_processor: C3: ACPI IOPORT 0x415 350 uS
>> xen_acpi_processor: ACPI CPU2 - C-states uploaded.
>> xen_acpi_processor: C1: ACPI HLT 1 uS
>> xen_acpi_processor: C2: ACPI IOPORT 0x414 18 uS
>> xen_acpi_processor: C3: ACPI IOPORT 0x415 350 uS
>> xen_acpi_processor: ACPI CPU2 - P-states uploaded.
>> xen_acpi_processor: *P0: 1700 MHz, 2071 mW, 0 uS
>> xen_acpi_processor: P1: 1600 MHz, 1520 mW, 0 uS
>> xen_acpi_processor: P2: 1400 MHz, 1277 mW, 0 uS
>> xen_acpi_processor: ACPI CPU3 - C-states uploaded.
>> xen_acpi_processor: C1: ACPI HLT 1 uS
>> xen_acpi_processor: C2: ACPI IOPORT 0x414 18 uS
>> xen_acpi_processor: C3: ACPI IOPORT 0x415 350 uS
>> xen_acpi_processor: ACPI CPU4 - C-states uploaded.
>> xen_acpi_processor: C1: ACPI HLT 1 uS
>> xen_acpi_processor: C2: ACPI IOPORT 0x414 18 uS
>> xen_acpi_processor: C3: ACPI IOPORT 0x415 350 uS
>> xen_acpi_processor: ACPI CPU4 - P-states uploaded.
>> xen_acpi_processor: *P0: 1700 MHz, 2071 mW, 0 uS
>> xen_acpi_processor: P1: 1600 MHz, 1520 mW, 0 uS
>> xen_acpi_processor: P2: 1400 MHz, 1277 mW, 0 uS
>> xen_acpi_processor: ACPI CPU5 - C-states uploaded.
>> xen_acpi_processor: C1: ACPI HLT 1 uS
>> xen_acpi_processor: C2: ACPI IOPORT 0x414 18 uS
>> xen_acpi_processor: C3: ACPI IOPORT 0x415 350 uS
>> xen_acpi_processor: ACPI CPU6 - C-states uploaded.
>> xen_acpi_processor: C1: ACPI HLT 1 uS
>> xen_acpi_processor: C2: ACPI IOPORT 0x414 18 uS
>> xen_acpi_processor: C3: ACPI IOPORT 0x415 350 uS
>> xen_acpi_processor: ACPI CPU6 - P-states uploaded.
>> xen_acpi_processor: *P0: 1700 MHz, 2071 mW, 0 uS
>> xen_acpi_processor: P1: 1600 MHz, 1520 mW, 0 uS
>> xen_acpi_processor: P2: 1400 MHz, 1277 mW, 0 uS
>> xen_acpi_processor: ACPI CPU7 - C-states uploaded.
>> xen_acpi_processor: C1: ACPI HLT 1 uS
>> xen_acpi_processor: C2: ACPI IOPORT 0x414 18 uS
>> xen_acpi_processor: C3: ACPI IOPORT 0x415 350 uS
>> xen_acpi_processor: ACPI CPU0 w/ PBLK:0x0
>> xen_acpi_processor: ACPI CPU0 w/ PST:coord_type = 254 domain = 0
>> xen_acpi_processor: CPU with ACPI ID 1 is unavailable
> Hm, that's weird, do you think you could check why it reports the CPU
> is unavailable?
If you would give me a hint at how I could check?
Right now my guess is that C state and P state is not in sync, thus P
state are for every other
CPU and C state is for the first 8. AFAIK AMD only have
performance-cores (unlike Intel).
>
> Overall I don't like the situation of the ACPI handling when running
> as dom0. It's fragile to rely on the data for dom0 CPUs to be
> filled by the system (by adding some band aids here and there so that
> the PV vCPUs are matched against the MADT objects) and then cloning
> the data for any physical CPU exceeding the number of dom0 virtual
> CPUs.
That's my understanding from earlier implementation as well, nobody
actually like it,
But the current solution is something working in a bad environment.
>
> IMO it would be much better to just do the handling of ACPI processor
> objects in a Xen specific driver (preventing the native driver from
> attaching) in order to fetch the data and upload it to Xen. This is
> what I've attempted to do on FreeBSD, and resulted in a cleaner
> implementation:
>
> <link>
>
> I however don't have time to do this right now for Linux.
Maybe I can take a stab, I very much like the climate of the kernel but
everything
seem so scary :) I've been trying to understand things better, how
they're all
connected.
>
>> xen_acpi_processor: ACPI CPU2 w/ PBLK:0x0
>> xen_acpi_processor: ACPI CPU2 w/ PST:coord_type = 254 domain = 1
>> xen_acpi_processor: CPU with ACPI ID 3 is unavailable
>> xen_acpi_processor: ACPI CPU4 w/ PBLK:0x0
>> xen_acpi_processor: ACPI CPU4 w/ PST:coord_type = 254 domain = 2
>> xen_acpi_processor: CPU with ACPI ID 5 is unavailable
>> xen_acpi_processor: ACPI CPU6 w/ PBLK:0x0
>> xen_acpi_processor: ACPI CPU6 w/ PST:coord_type = 254 domain = 3
>> xen_acpi_processor: CPU with ACPI ID 7 is unavailable
>> xen_acpi_processor: ACPI CPU8 w/ PBLK:0x0
>> xen_acpi_processor: ACPI CPU8 w/ PST:coord_type = 254 domain = 4
>> xen_acpi_processor: CPU with ACPI ID 9 is unavailable
>> xen_acpi_processor: ACPI CPU10 w/ PBLK:0x0
>> xen_acpi_processor: ACPI CPU10 w/ PST:coord_type = 254 domain = 5
>> xen_acpi_processor: CPU with ACPI ID 11 is unavailable
>> xen_acpi_processor: ACPI CPU12 w/ PBLK:0x0
>> xen_acpi_processor: ACPI CPU12 w/ PST:coord_type = 254 domain = 6
>> xen_acpi_processor: CPU with ACPI ID 13 is unavailable
>> xen_acpi_processor: ACPI CPU14 w/ PBLK:0x0
>> xen_acpi_processor: ACPI CPU14 w/ PST:coord_type = 254 domain = 7
>> xen_acpi_processor: CPU with ACPI ID 15 is unavailable
>> xen_acpi_processor: ACPI CPU8 - P-states uploaded.
>> xen_acpi_processor: *P0: 1700 MHz, 2071 mW, 0 uS
>> xen_acpi_processor: P1: 1600 MHz, 1520 mW, 0 uS
>> xen_acpi_processor: P2: 1400 MHz, 1277 mW, 0 uS
>> xen_acpi_processor: ACPI CPU10 - P-states uploaded.
>> xen_acpi_processor: *P0: 1700 MHz, 2071 mW, 0 uS
>> xen_acpi_processor: P1: 1600 MHz, 1520 mW, 0 uS
>> xen_acpi_processor: P2: 1400 MHz, 1277 mW, 0 uS
>> xen_acpi_processor: ACPI CPU12 - P-states uploaded.
>> xen_acpi_processor: *P0: 1700 MHz, 2071 mW, 0 uS
>> xen_acpi_processor: P1: 1600 MHz, 1520 mW, 0 uS
>> xen_acpi_processor: P2: 1400 MHz, 1277 mW, 0 uS
>> xen_acpi_processor: ACPI CPU14 - P-states uploaded.
>> xen_acpi_processor: *P0: 1700 MHz, 2071 mW, 0 uS
>> xen_acpi_processor: P1: 1600 MHz, 1520 mW, 0 uS
>> xen_acpi_processor: P2: 1400 MHz, 1277 mW, 0 uS
>>
>> As a bonus, here are the previous debug output on the same machine.
> I think the output below is with dom0 running as plain PV rather than
> PVH?
This is the upstream ACPI implementation vs yours. What would plain PV
vs PVH be in dom0?
Regards
- Josef
> Thanks, Roger.
On Thu, Mar 16, 2023 at 08:54:57AM +0100, Josef Johansson wrote:
> On 3/15/23 12:39, Roger Pau Monné wrote:
> > On Mon, Jan 30, 2023 at 10:10:05AM +0100, Josef Johansson wrote:
> > > On 11/21/22 11:21, Roger Pau Monne wrote:
> > > > When running as a PVH dom0 the ACPI MADT is crafted by Xen in order to
> > > > report the correct numbers of vCPUs that dom0 has, so the host MADT is
> > > > not provided to dom0. This creates issues when parsing the power and
> > > > performance related data from ACPI dynamic tables, as the ACPI
> > > > Processor UIDs found on the dynamic code are likely to not match the
> > > > ones crafted by Xen in the dom0 MADT.
> > > >
> > > > Xen would rely on Linux having filled at least the power and
> > > > performance related data of the vCPUs on the system, and would clone
> > > > that information in order to setup the remaining pCPUs on the system
> > > > if dom0 vCPUs < pCPUs. However when running as PVH dom0 it's likely
> > > > that none of dom0 CPUs will have the power and performance data
> > > > filled, and hence the Xen ACPI Processor driver needs to fetch that
> > > > information by itself.
> > > >
> > > > In order to do so correctly, introduce a new helper to fetch the _CST
> > > > data without taking into account the system capabilities from the
> > > > CPUID output, as the capabilities reported to dom0 in CPUID might be
> > > > different from the ones on the host.
> > > >
> > > >
> > > Hi Roger,
> > >
> > > First of all, thanks for doing the grunt work here to clear up the ACPI
> > > situation.
> > >
> > > A bit of background, I'm trying to get an AMD APU (CPUID 0x17 (23)) to work
> > > properly
> > > under Xen. It works fine otherwise but something is amiss under Xen.
> > Hello,
> >
> > Sorry for the delay, I've been on paternity leave and just caching up
> > on emails.
> Hi Roger,
>
> Congratulations! I hope you had time to really connect. It's the most
> important thing we can do here in life.
>
> I came into this to understand each and every error in my boot-log, it turns
> out that the latest
> kernel+xen+firmware fixes suspend/resume for me, thus is this not related.
> But as I pointed out,
> the output does not make any sense (nor yours nor the upstream). I should
> check the debug
> output with suspend working fine now to see if there are any changes, that
> would be quite
> interesting.
>
> Also, I should mention that your patch broke some things on my system and
> made it
> unstable. I don't remember exactly and I know you said that this is more of
> a PoC. Just a
> heads up.
Right, I don't plan to send the PVH part just now, and instead I'm
focusing in the first patch that should fix _PDC evaluation for PV
dom0. I will Cc you on the last version so you can give it a try and
assert is not regressing stuff for you.
> > > Just to make sure that the patch is working as intended, what I found when
> > > trying it out
> > > is that the first 8 CPUs have C-States, but 0, 2, 4, 6, 8, 10, 12, 14 have
> > > P-States, out of
> > > 16 CPUs. Xen tells Linux that there are 8 CPUs since it's running with
> > > nosmt.
> > >
> > > Regards
> > > - Josef
> > >
> > > xen_acpi_processor: Max ACPI ID: 30
> > > xen_acpi_processor: Uploading Xen processor PM info
> > > xen_acpi_processor: ACPI CPU0 - C-states uploaded.
> > > xen_acpi_processor: C1: ACPI HLT 1 uS
> > > xen_acpi_processor: C2: ACPI IOPORT 0x414 18 uS
> > > xen_acpi_processor: C3: ACPI IOPORT 0x415 350 uS
> > > xen_acpi_processor: ACPI CPU0 - P-states uploaded.
> > > xen_acpi_processor: *P0: 1700 MHz, 2071 mW, 0 uS
> > > xen_acpi_processor: P1: 1600 MHz, 1520 mW, 0 uS
> > > xen_acpi_processor: P2: 1400 MHz, 1277 mW, 0 uS
> > > xen_acpi_processor: ACPI CPU1 - C-states uploaded.
> > > xen_acpi_processor: C1: ACPI HLT 1 uS
> > > xen_acpi_processor: C2: ACPI IOPORT 0x414 18 uS
> > > xen_acpi_processor: C3: ACPI IOPORT 0x415 350 uS
> > > xen_acpi_processor: ACPI CPU2 - C-states uploaded.
> > > xen_acpi_processor: C1: ACPI HLT 1 uS
> > > xen_acpi_processor: C2: ACPI IOPORT 0x414 18 uS
> > > xen_acpi_processor: C3: ACPI IOPORT 0x415 350 uS
> > > xen_acpi_processor: ACPI CPU2 - P-states uploaded.
> > > xen_acpi_processor: *P0: 1700 MHz, 2071 mW, 0 uS
> > > xen_acpi_processor: P1: 1600 MHz, 1520 mW, 0 uS
> > > xen_acpi_processor: P2: 1400 MHz, 1277 mW, 0 uS
> > > xen_acpi_processor: ACPI CPU3 - C-states uploaded.
> > > xen_acpi_processor: C1: ACPI HLT 1 uS
> > > xen_acpi_processor: C2: ACPI IOPORT 0x414 18 uS
> > > xen_acpi_processor: C3: ACPI IOPORT 0x415 350 uS
> > > xen_acpi_processor: ACPI CPU4 - C-states uploaded.
> > > xen_acpi_processor: C1: ACPI HLT 1 uS
> > > xen_acpi_processor: C2: ACPI IOPORT 0x414 18 uS
> > > xen_acpi_processor: C3: ACPI IOPORT 0x415 350 uS
> > > xen_acpi_processor: ACPI CPU4 - P-states uploaded.
> > > xen_acpi_processor: *P0: 1700 MHz, 2071 mW, 0 uS
> > > xen_acpi_processor: P1: 1600 MHz, 1520 mW, 0 uS
> > > xen_acpi_processor: P2: 1400 MHz, 1277 mW, 0 uS
> > > xen_acpi_processor: ACPI CPU5 - C-states uploaded.
> > > xen_acpi_processor: C1: ACPI HLT 1 uS
> > > xen_acpi_processor: C2: ACPI IOPORT 0x414 18 uS
> > > xen_acpi_processor: C3: ACPI IOPORT 0x415 350 uS
> > > xen_acpi_processor: ACPI CPU6 - C-states uploaded.
> > > xen_acpi_processor: C1: ACPI HLT 1 uS
> > > xen_acpi_processor: C2: ACPI IOPORT 0x414 18 uS
> > > xen_acpi_processor: C3: ACPI IOPORT 0x415 350 uS
> > > xen_acpi_processor: ACPI CPU6 - P-states uploaded.
> > > xen_acpi_processor: *P0: 1700 MHz, 2071 mW, 0 uS
> > > xen_acpi_processor: P1: 1600 MHz, 1520 mW, 0 uS
> > > xen_acpi_processor: P2: 1400 MHz, 1277 mW, 0 uS
> > > xen_acpi_processor: ACPI CPU7 - C-states uploaded.
> > > xen_acpi_processor: C1: ACPI HLT 1 uS
> > > xen_acpi_processor: C2: ACPI IOPORT 0x414 18 uS
> > > xen_acpi_processor: C3: ACPI IOPORT 0x415 350 uS
> > > xen_acpi_processor: ACPI CPU0 w/ PBLK:0x0
> > > xen_acpi_processor: ACPI CPU0 w/ PST:coord_type = 254 domain = 0
> > > xen_acpi_processor: CPU with ACPI ID 1 is unavailable
> > Hm, that's weird, do you think you could check why it reports the CPU
> > is unavailable?
> If you would give me a hint at how I could check?
It likely requires you to add printk statements to the kernel in order
to figure out which conditional fails when running as a PVH dom0.
> Right now my guess is that C state and P state is not in sync, thus P state
> are for every other
> CPU and C state is for the first 8. AFAIK AMD only have performance-cores
> (unlike Intel).
Linux thinking the CPU is not online is more likely to be due to the
ACPI ID differences when running as a PVH dom0. Anyway, I will try to
revisit this and figure out what's wrong.
> >
> > Overall I don't like the situation of the ACPI handling when running
> > as dom0. It's fragile to rely on the data for dom0 CPUs to be
> > filled by the system (by adding some band aids here and there so that
> > the PV vCPUs are matched against the MADT objects) and then cloning
> > the data for any physical CPU exceeding the number of dom0 virtual
> > CPUs.
> That's my understanding from earlier implementation as well, nobody actually
> like it,
> But the current solution is something working in a bad environment.
> >
> > IMO it would be much better to just do the handling of ACPI processor
> > objects in a Xen specific driver (preventing the native driver from
> > attaching) in order to fetch the data and upload it to Xen. This is
> > what I've attempted to do on FreeBSD, and resulted in a cleaner
> > implementation:
> >
> > <link>
> >
> > I however don't have time to do this right now for Linux.
>
> Maybe I can take a stab, I very much like the climate of the kernel but
> everything
> seem so scary :) I've been trying to understand things better, how they're
> all
> connected.
> >
> > > xen_acpi_processor: ACPI CPU2 w/ PBLK:0x0
> > > xen_acpi_processor: ACPI CPU2 w/ PST:coord_type = 254 domain = 1
> > > xen_acpi_processor: CPU with ACPI ID 3 is unavailable
> > > xen_acpi_processor: ACPI CPU4 w/ PBLK:0x0
> > > xen_acpi_processor: ACPI CPU4 w/ PST:coord_type = 254 domain = 2
> > > xen_acpi_processor: CPU with ACPI ID 5 is unavailable
> > > xen_acpi_processor: ACPI CPU6 w/ PBLK:0x0
> > > xen_acpi_processor: ACPI CPU6 w/ PST:coord_type = 254 domain = 3
> > > xen_acpi_processor: CPU with ACPI ID 7 is unavailable
> > > xen_acpi_processor: ACPI CPU8 w/ PBLK:0x0
> > > xen_acpi_processor: ACPI CPU8 w/ PST:coord_type = 254 domain = 4
> > > xen_acpi_processor: CPU with ACPI ID 9 is unavailable
> > > xen_acpi_processor: ACPI CPU10 w/ PBLK:0x0
> > > xen_acpi_processor: ACPI CPU10 w/ PST:coord_type = 254 domain = 5
> > > xen_acpi_processor: CPU with ACPI ID 11 is unavailable
> > > xen_acpi_processor: ACPI CPU12 w/ PBLK:0x0
> > > xen_acpi_processor: ACPI CPU12 w/ PST:coord_type = 254 domain = 6
> > > xen_acpi_processor: CPU with ACPI ID 13 is unavailable
> > > xen_acpi_processor: ACPI CPU14 w/ PBLK:0x0
> > > xen_acpi_processor: ACPI CPU14 w/ PST:coord_type = 254 domain = 7
> > > xen_acpi_processor: CPU with ACPI ID 15 is unavailable
> > > xen_acpi_processor: ACPI CPU8 - P-states uploaded.
> > > xen_acpi_processor: *P0: 1700 MHz, 2071 mW, 0 uS
> > > xen_acpi_processor: P1: 1600 MHz, 1520 mW, 0 uS
> > > xen_acpi_processor: P2: 1400 MHz, 1277 mW, 0 uS
> > > xen_acpi_processor: ACPI CPU10 - P-states uploaded.
> > > xen_acpi_processor: *P0: 1700 MHz, 2071 mW, 0 uS
> > > xen_acpi_processor: P1: 1600 MHz, 1520 mW, 0 uS
> > > xen_acpi_processor: P2: 1400 MHz, 1277 mW, 0 uS
> > > xen_acpi_processor: ACPI CPU12 - P-states uploaded.
> > > xen_acpi_processor: *P0: 1700 MHz, 2071 mW, 0 uS
> > > xen_acpi_processor: P1: 1600 MHz, 1520 mW, 0 uS
> > > xen_acpi_processor: P2: 1400 MHz, 1277 mW, 0 uS
> > > xen_acpi_processor: ACPI CPU14 - P-states uploaded.
> > > xen_acpi_processor: *P0: 1700 MHz, 2071 mW, 0 uS
> > > xen_acpi_processor: P1: 1600 MHz, 1520 mW, 0 uS
> > > xen_acpi_processor: P2: 1400 MHz, 1277 mW, 0 uS
> > >
> > > As a bonus, here are the previous debug output on the same machine.
> > I think the output below is with dom0 running as plain PV rather than
> > PVH?
> This is the upstream ACPI implementation vs yours. What would plain PV vs
> PVH be in dom0?
But that's always with Linux running as a dom0, or just running bare
metal?
Thanks, Roger.