Pull hyperv fixes from Wei Liu:

 - Various fixes to Hyper-V tools in the kernel tree (Dexuan Cui, Olaf
   Hering, Vitaly Kuznetsov)

 - Fix a bug in the Hyper-V TSC page based sched_clock() (Naman Jain)

 - Two bug fixes in the Hyper-V utility functions (Michael Kelley)

 - Convert open-coded timeouts to secs_to_jiffies() in Hyper-V drivers
   (Easwar Hariharan)

* tag 'hyperv-fixes-signed-20241217' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
  tools/hv: reduce resource usage in hv_kvp_daemon
  tools/hv: add a .gitignore file
  tools/hv: reduce resouce usage in hv_get_dns_info helper
  hv/hv_kvp_daemon: Pass NIC name to hv_get_dns_info as well
  Drivers: hv: util: Avoid accessing a ringbuffer not initialized yet
  Drivers: hv: util: Don't force error code to ENODEV in util_probe()
  tools/hv: terminate fcopy daemon if read from uio fails
  drivers: hv: Convert open-coded timeouts to secs_to_jiffies()
  tools: hv: change permissions of NetworkManager configuration file
  x86/hyperv: Fix hv tsc page based sched_clock for hibernation
  tools: hv: Fix a complier warning in the fcopy uio daemon

The hypercall page is no longer needed. It can be removed, as from the
Xen perspective it is optional.

But, from Linux's perspective, it removes naked RET instructions that
escape the speculative protections that Call Depth Tracking and/or
Untrain Ret are trying to achieve.

This is part of XSA-466 / CVE-2024-53241.

Reported-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>

Add static_call_update_early() for updating static-call targets in
very early boot.

This will be needed for support of Xen guest type specific hypercall
functions.

This is part of XSA-466 / CVE-2024-53241.

Reported-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Co-developed-by: Peter Zijlstra <peterz@infradead.org>
Co-developed-by: Josh Poimboeuf <jpoimboe@redhat.com>

In order to be able to differentiate between AMD and Intel based
systems for very early hypercalls without having to rely on the Xen
hypercall page, make get_cpu_vendor() non-static.

Refactor early_cpu_init() for the same reason by splitting out the
loop initializing cpu_devs() into an externally callable function.

This is part of XSA-466 / CVE-2024-53241.

Reported-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Juergen Gross <jgross@suse.com>

read_hv_sched_clock_tsc() assumes that the Hyper-V clock counter is
bigger than the variable hv_sched_clock_offset, which is cached during
early boot, but depending on the timing this assumption may be false
when a hibernated VM starts again (the clock counter starts from 0
again) and is resuming back (Note: hv_init_tsc_clocksource() is not
called during hibernation/resume); consequently,
read_hv_sched_clock_tsc() may return a negative integer (which is
interpreted as a huge positive integer since the return type is u64)
and new kernel messages are prefixed with huge timestamps before
read_hv_sched_clock_tsc() grows big enough (which typically takes
several seconds).

Fix the issue by saving the Hyper-V clock counter just before the
suspend, and using it to correct the hv_sched_clock_offset in
resume. This makes hv tsc page based sched_clock continuous and ensures
that post resume, it starts from where it left off during suspend.
Override x86_platform.save_sched_clock_state and
x86_platform.restore_sched_clock_state routines to correct this as soon
as possible.

Note: if Invariant TSC is available, the issue doesn't happen because
1) we don't register read_hv_sched_clock_tsc() for sched clock:
See commit e5313f1c5404 ("clocksource/drivers/hyper-v: Rework
clocksource and sched clock setup");
2) the common x86 code adjusts TSC similarly: see
__restore_processor_state() ->  tsc_verify_tsc_adjust(true) and
x86_platform.restore_sched_clock_state().

Cc: stable@vger.kernel.org
Fixes: 1349401ff1aa ("clocksource/drivers/hyper-v: Suspend/resume Hyper-V clocksource for hibernation")
Co-developed-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Naman Jain <namjain@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Link: https://lore.kernel.org/r/20240917053917.76787-1-namjain@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Message-ID: <20240917053917.76787-1-namjain@linux.microsoft.com>

Build 6.13-rc12 for x86_64 with gcc 14.2.1 fails with the error:

  ld: vmlinux.o: in function `virtual_mapped':
  linux/arch/x86/kernel/relocate_kernel_64.S:249:(.text+0x5915b): undefined reference to `saved_context_gdt_desc'

when CONFIG_KEXEC_JUMP is enabled.

This was introduced by commit 07fa619f2a40 ("x86/kexec: Restore GDT on
return from ::preserve_context kexec") which introduced a use of
saved_context_gdt_desc without a declaration for it.

Fix that by including asm/asm-offsets.h where saved_context_gdt_desc
is defined (indirectly in include/generated/asm-offsets.h which
asm/asm-offsets.h includes).

Fixes: 07fa619f2a40 ("x86/kexec: Restore GDT on return from ::preserve_context kexec")
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Acked-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: David Woodhouse <dwmw@amazon.co.uk>
Closes: https://lore.kernel.org/oe-kbuild-all/202411270006.ZyyzpYf8-lkp@intel.com/
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

When ensuring EFER.AUTOIBRS is set, WARN only on a negative return code
from msr_set_bit(), as '1' is used to indicate the WRMSR was successful
('0' indicates the MSR bit was already set).

Fixes: 8cc68c9c9e92 ("x86/CPU/AMD: Make sure EFER[AIBRSE] is set")
Reported-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/Z1MkNofJjt7Oq0G6@google.com
Closes: https://lore.kernel.org/all/20241205220604.GA2054199@thelio-3990X

Linux remembers cpu_cachinfo::num_leaves per CPU, but x86 initializes all
CPUs from the same global "num_cache_leaves".

This is erroneous on systems such as Meteor Lake, where each CPU has a
distinct num_leaves value. Delete the global "num_cache_leaves" and
initialize num_leaves on each CPU.

init_cache_level() no longer needs to set num_leaves. Also, it never had to
set num_levels as it is unnecessary in x86. Keep checking for zero cache
leaves. Such condition indicates a bug.

  [ bp: Cleanup. ]

Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Cc: stable@vger.kernel.org # 6.3+
Link: https://lore.kernel.org/r/20241128002247.26726-3-ricardo.neri-calderon@linux.intel.com

The restore_processor_state() function explicitly states that "the asm code
that gets us here will have restored a usable GDT". That wasn't true in the
case of returning from a ::preserve_context kexec. Make it so.

Without this, the kernel was depending on the called function to reload a
GDT which is appropriate for the kernel before returning.

Test program:

 #include <unistd.h>
 #include <errno.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <linux/kexec.h>
 #include <linux/reboot.h>
 #include <sys/reboot.h>
 #include <sys/syscall.h>

 int main (void)
 {
        struct kexec_segment segment = {};
	unsigned char purgatory[] = {
		0x66, 0xba, 0xf8, 0x03,	// mov $0x3f8, %dx
		0xb0, 0x42,		// mov $0x42, %al
		0xee,			// outb %al, (%dx)
		0xc3,			// ret
	};
	int ret;

	segment.buf = &purgatory;
	segment.bufsz = sizeof(purgatory);
	segment.mem = (void *)0x400000;
	segment.memsz = 0x1000;
	ret = syscall(__NR_kexec_load, 0x400000, 1, &segment, KEXEC_PRESERVE_CONTEXT);
	if (ret) {
		perror("kexec_load");
		exit(1);
	}

	ret = syscall(__NR_reboot, LINUX_REBOOT_MAGIC1, LINUX_REBOOT_MAGIC2, LINUX_REBOOT_CMD_KEXEC);
	if (ret) {
		perror("kexec reboot");
		exit(1);
	}
	printf("Success\n");
	return 0;
 }

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20241205153343.3275139-2-dwmw2@infradead.org

The rework of possible CPUs management erroneously disabled SMP when the
IO/APIC is disabled either by the 'noapic' command line parameter or during
IO/APIC setup. SMP is possible without IO/APIC.

Remove the ioapic_is_disabled conditions from the relevant possible CPU
management code paths to restore the orgininal behaviour.

Fixes: 7c0edad3643f ("x86/cpu/topology: Rework possible CPU management")
Signed-off-by: Fernando Fernandez Mancera <ffmancera@riseup.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/all/20241202145905.1482-1-ffmancera@riseup.net