treewide: Remove system_counterval_t.cs, which is never read

The clocksource pointer in struct system_counterval_t is not evaluated any
more. Remove the code setting the member, and the member itself.

Signed-off-by: Peter Hilber <peter.hilber@opensynergy.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240201010453.2212371-8-peter.hilber@opensynergy.com

ptp/kvm, arm_arch_timer: Set system_counterval_t.cs_id to constant

Identify the clocksources used by ptp_kvm by setting the clocksource ID
enum constants. This avoids dereferencing struct clocksource. Once the
system_counterval_t.cs member will be removed, this will also avoid the
need to obtain clocksource pointers from kvm_arch_ptp_get_crosststamp().

The clocksource IDs are associated to timestamps requested from the KVM
hypervisor, so the proper clocksource ID is known at the ptp_kvm request
site.

While at it, also make the ptp_kvm_get_time_fn() 'ret' variable type int as
that's what the function return value is.

Signed-off-by: Peter Hilber <peter.hilber@opensynergy.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240201010453.2212371-6-peter.hilber@opensynergy.com

x86/kvm, ptp/kvm: Add clocksource ID, set system_counterval_t.cs_id

Add a clocksource ID for the x86 kvmclock.

Also, for ptp_kvm, set the recently added struct system_counterval_t member
cs_id to the clocksource ID (x86 kvmclock or ARM Generic Timer). In the
future, get_device_system_crosststamp() will compare the clocksource ID in
struct system_counterval_t, rather than the clocksource.

For now, to avoid touching too many subsystems at once, extract the
clocksource ID from the clocksource. The clocksource dereference will be
removed once everything is converted over..

Signed-off-by: Peter Hilber <peter.hilber@opensynergy.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240201010453.2212371-5-peter.hilber@opensynergy.com

ptp: kvm: Use decrypted memory in confidential guest on x86

KVM_HC_CLOCK_PAIRING currently fails inside SEV-SNP guests because the
guest passes an address to static data to the host. In confidential
computing the host can't access arbitrary guest memory so handling the
hypercall runs into an "rmpfault". To make the hypercall work, the guest
needs to explicitly mark the memory as decrypted. Do that in
kvm_arch_ptp_init(), but retain the previous behavior for
non-confidential guests to save us from having to allocate memory.

Add a new arch-specific function (kvm_arch_ptp_exit()) to free the
allocation and mark the memory as encrypted again.

Signed-off-by: Jeremi Piotrowski <jpiotrowski@linux.microsoft.com>
Link: https://lore.kernel.org/r/20230308150531.477741-1-jpiotrowski@linux.microsoft.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers: convert unsupported .adjfreq to .adjfine

A few PTP drivers implement a .adjfreq handler which indicates the
operation is not supported. Convert all of these to .adjfine.

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Wei Liu <wei.liu@kernel.org>
Cc: Dexuan Cui <decui@microsoft.com>
Cc: Vivek Thampi <vithampi@vmware.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ptp: Don't print an error if ptp_kvm is not supported

Commit 300bb1fe7671 ("ptp: arm/arm64: Enable ptp_kvm for arm/arm64")
enable ptp_kvm support for ARM platforms and for any ARM platform that
does not support this, the following error message is displayed ...

ERR KERN fail to initialize ptp_kvm

For platforms that do not support ptp_kvm this error is a bit misleading
and so fix this by only printing this message if the error returned by
kvm_arch_ptp_init() is not -EOPNOTSUPP. Note that -EOPNOTSUPP is only
returned by ARM platforms today if ptp_kvm is not supported.

Fixes: 300bb1fe7671 ("ptp: arm/arm64: Enable ptp_kvm for arm/arm64")
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210420132419.1318148-1-jonathanh@nvidia.com

ptp: Reorganize ptp_kvm.c to make it arch-independent

Currently, the ptp_kvm module contains a lot of x86-specific code.
Let's move this code into a new arch-specific file in the same directory,
and rename the arch-independent file to ptp_kvm_common.c.

Acked-by: Richard Cochran <richardcochran@gmail.com>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Jianyong Wu <jianyong.wu@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201209060932.212364-4-jianyong.wu@arm.com