Re: [PATCH] KVM: x86: Revert kvm_x86_ops.mem_enc_ioctl() back to an OPTIONAL hook

From: Sean Christopherson
Date: Fri May 02 2025 - 17:55:39 EST


On Fri, 02 May 2025 13:34:21 -0700, Sean Christopherson wrote:
> Restore KVM's handling of a NULL kvm_x86_ops.mem_enc_ioctl, as the hook is
> NULL on SVM when CONFIG_KVM_AMD_SEV=n, and TDX will soon follow suit.
>
> ------------[ cut here ]------------
> WARNING: CPU: 0 PID: 1 at arch/x86/include/asm/kvm-x86-ops.h:130 kvm_x86_vendor_init+0x178b/0x18e0
> Modules linked in:
> CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.15.0-rc2-dc1aead1a985-sink-vm #2 NONE
> Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
> RIP: 0010:kvm_x86_vendor_init+0x178b/0x18e0
> Call Trace:
> <TASK>
> svm_init+0x2e/0x60
> do_one_initcall+0x56/0x290
> kernel_init_freeable+0x192/0x1e0
> kernel_init+0x16/0x130
> ret_from_fork+0x30/0x50
> ret_from_fork_asm+0x1a/0x30
> </TASK>
> ---[ end trace 0000000000000000 ]---
>
> [...]

Applied very quickly to kvm-x86 vmx, as I want to get the TDX macro cleanups
applied. I'll force push if someone finds an issue.

[1/1] KVM: x86: Revert kvm_x86_ops.mem_enc_ioctl() back to an OPTIONAL hook
https://github.com/kvm-x86/linux/commit/f2d7993314a3

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https://github.com/kvm-x86/linux/tree/next