On 02/04/20 04:36, Stephen Rothwell wrote:
> Hi all,
>
> Today's linux-next merge of the kvm tree got a conflict in:
>
> arch/x86/kvm/svm/svm.c
>
> between commits:
>
> aaca21007ba1 ("KVM: SVM: Fix the svm vmexit code for WRMSR")
> 2da1ed62d55c ("KVM: SVM: document KVM_MEM_ENCRYPT_OP, let userspace detect if SEV is available")
> 2e2409afe5f0 ("KVM: SVM: Issue WBINVD after deactivating an SEV guest")
>
> from Linus' tree and commits:
>
> 83a2c705f002 ("kVM SVM: Move SVM related files to own sub-directory")
> 41f08f0506c0 ("KVM: SVM: Move SEV code to separate file")
>
> (at least)
>
> from the kvm tree.
>
> Its a bit of a pain this code movement appearing during the merge
> window. Is it really intended for v5.7?
I'll send two separate pull requests to Linus so that he doesn't see the
issues introduced by the code movement.
Paolo
> I fixed it up (see below) and can carry the fix as necessary. This
> is now fixed as far as linux-next is concerned, but any non trivial
> conflicts should be mentioned to your upstream maintainer when your tree
> is submitted for merging. You may also want to consider cooperating
> with the maintainer of the conflicting tree to minimise any particularly
> complex conflicts.
>
> diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
> index 621a36702636..2be5bbae3a40 100644
> --- a/arch/x86/kvm/svm/svm.c
> +++ b/arch/x86/kvm/svm/svm.c
> @@ -34,6 +34,7 @@
> #include <asm/kvm_para.h>
> #include <asm/irq_remapping.h>
> #include <asm/spec-ctrl.h>
> +#include <asm/cpu_device_id.h>
>
> #include <asm/virtext.h>
> #include "trace.h"
> @@ -47,7 +48,7 @@ MODULE_LICENSE("GPL");
>
> #ifdef MODULE
> static const struct x86_cpu_id svm_cpu_id[] = {
> - X86_FEATURE_MATCH(X86_FEATURE_SVM),
> + X86_MATCH_FEATURE(X86_FEATURE_SVM, NULL),
> {}
> };
> MODULE_DEVICE_TABLE(x86cpu, svm_cpu_id);
> @@ -3715,7 +3716,8 @@ static void svm_handle_exit_irqoff(struct kvm_vcpu *vcpu,
> enum exit_fastpath_completion *exit_fastpath)
> {
> if (!is_guest_mode(vcpu) &&
> - to_svm(vcpu)->vmcb->control.exit_code == EXIT_REASON_MSR_WRITE)
> + to_svm(vcpu)->vmcb->control.exit_code == SVM_EXIT_MSR &&
> + to_svm(vcpu)->vmcb->control.exit_info_1)
> *exit_fastpath = handle_fastpath_set_msr_irqoff(vcpu);
> }
>
> diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
> index 3ef57dee48cc..0e3fc311d7da 100644
> --- a/arch/x86/kvm/svm/sev.c
> +++ b/arch/x86/kvm/svm/sev.c
> @@ -920,6 +920,9 @@ int svm_mem_enc_op(struct kvm *kvm, void __user *argp)
> if (!svm_sev_enabled())
> return -ENOTTY;
>
> + if (!argp)
> + return 0;
> +
> if (copy_from_user(&sev_cmd, argp, sizeof(struct kvm_sev_cmd)))
> return -EFAULT;
>
> @@ -1030,14 +1033,6 @@ find_enc_region(struct kvm *kvm, struct kvm_enc_region *range)
> static void __unregister_enc_region_locked(struct kvm *kvm,
> struct enc_region *region)
> {
> - /*
> - * The guest may change the memory encryption attribute from C=0 -> C=1
> - * or vice versa for this memory range. Lets make sure caches are
> - * flushed to ensure that guest data gets written into memory with
> - * correct C-bit.
> - */
> - sev_clflush_pages(region->pages, region->npages);
> -
> sev_unpin_memory(kvm, region->pages, region->npages);
> list_del(®ion->list);
> kfree(region);
> @@ -1062,6 +1057,13 @@ int svm_unregister_enc_region(struct kvm *kvm,
> goto failed;
> }
>
> + /*
> + * Ensure that all guest tagged cache entries are flushed before
> + * releasing the pages back to the system for use. CLFLUSH will
> + * not do this, so issue a WBINVD.
> + */
> + wbinvd_on_all_cpus();
> +
> __unregister_enc_region_locked(kvm, region);
>
> mutex_unlock(&kvm->lock);
> @@ -1083,6 +1085,13 @@ void sev_vm_destroy(struct kvm *kvm)
>
> mutex_lock(&kvm->lock);
>
> + /*
> + * Ensure that all guest tagged cache entries are flushed before
> + * releasing the pages back to the system for use. CLFLUSH will
> + * not do this, so issue a WBINVD.
> + */
> + wbinvd_on_all_cpus();
> +
> /*
> * if userspace was terminated before unregistering the memory regions
> * then lets unpin all the registered memory.
>
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