On 4/29/2025 8:42 PM, Michael Kelley wrote:
From: Roman Kisel <rom...@linux.microsoft.com> Sent: Monday, April 28, 2025 11:27 AMTo start an application processor in SNP-isolated guest, a hypercall is used that takes a virtual processor index. The hv_snp_boot_ap() function uses that START_VP hypercall but passes as VP index to it what it receives as a wakeup_secondary_cpu_64 callback: the APIC ID. As those two aren't generally interchangeable, that may lead to hung APs if the VP index and the APIC ID don't match up. Update the parameter names to avoid confusion as to what the parameter is. Use the APIC ID to the VP index conversion to provide the correct input to the hypercall. Cc: sta...@vger.kernel.org Fixes: 44676bb9d566 ("x86/hyperv: Add smp support for SEV-SNP guest") Signed-off-by: Roman Kisel <rom...@linux.microsoft.com> --- [V3] - Removed the misleading comment about the APIC ID and VP indices. - Removed the not sufficiently founded if statement that was added to the previous version of the patch to avoid the O(n) time complexity. I'll follow up with a separate patch to address that as that pattern has crept into other places in the code in the AP wakeup path. - Fixed the logging message to use the "VP index" terminology consistently. ** Thank you, Michael! ** [V2] https://lore.kernel.org/linux-hyperv/20250425213512.1837061-1-rom...@linux.microsoft.com/ - Fixed the terminology in the patch and other code to use the term "VP index" consistently ** Thank you, Michael! ** - Missed not enabling the SNP-SEV options in the local testing, and sent a patch that breaks the build. ** Thank you, Saurabh! ** - Added comments and getting the Linux kernel CPU number from the available data. [V1] https://lore.kernel.org/linux-hyperv/20250424215746.467281-1-rom...@linux.microsoft.com/ --- arch/x86/hyperv/hv_init.c | 33 +++++++++++++++++++++++++ arch/x86/hyperv/hv_vtl.c | 44 +++++---------------------------- arch/x86/hyperv/ivm.c | 22 +++++++++++++++-- arch/x86/include/asm/mshyperv.h | 6 +++-- include/hyperv/hvgdk_mini.h | 2 +- 5 files changed, 64 insertions(+), 43 deletions(-)Thanks for fixing the terminology, in addition to fixing the bug that is your original purpose for the patch.
Thanks for your support and feedback :)
Reviewed-by: Michael Kelley <mhkli...@outlook.com>
-- Thank you, Roman
