diff options
| author | Quentin Perret <qperret@google.com> | 2021-12-15 16:12:31 +0000 |
|---|---|---|
| committer | Marc Zyngier <maz@kernel.org> | 2021-12-16 12:58:57 +0000 |
| commit | 52b28657ebd7cd20e931ce71190f235d0fa018a6 (patch) | |
| tree | 98a6a0f27ff745cddbccc2f4dbbd3033e73712af /arch/arm64/kvm/fpsimd.c | |
| parent | b8cc6eb5bded7078f796b2ebf548f79850281eb6 (diff) | |
KVM: arm64: pkvm: Unshare guest structs during teardown
Make use of the newly introduced unshare hypercall during guest teardown
to unmap guest-related data structures from the hyp stage-1.
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211215161232.1480836-15-qperret@google.com
Diffstat (limited to 'arch/arm64/kvm/fpsimd.c')
| -rw-r--r-- | arch/arm64/kvm/fpsimd.c | 34 |
1 files changed, 31 insertions, 3 deletions
diff --git a/arch/arm64/kvm/fpsimd.c b/arch/arm64/kvm/fpsimd.c index 86899d3aa9a9..2f48fd362a8c 100644 --- a/arch/arm64/kvm/fpsimd.c +++ b/arch/arm64/kvm/fpsimd.c @@ -14,6 +14,19 @@ #include <asm/kvm_mmu.h> #include <asm/sysreg.h> +void kvm_vcpu_unshare_task_fp(struct kvm_vcpu *vcpu) +{ + struct task_struct *p = vcpu->arch.parent_task; + struct user_fpsimd_state *fpsimd; + + if (!is_protected_kvm_enabled() || !p) + return; + + fpsimd = &p->thread.uw.fpsimd_state; + kvm_unshare_hyp(fpsimd, fpsimd + 1); + put_task_struct(p); +} + /* * Called on entry to KVM_RUN unless this vcpu previously ran at least * once and the most recent prior KVM_RUN for this vcpu was called from @@ -29,12 +42,27 @@ int kvm_arch_vcpu_run_map_fp(struct kvm_vcpu *vcpu) struct user_fpsimd_state *fpsimd = ¤t->thread.uw.fpsimd_state; + kvm_vcpu_unshare_task_fp(vcpu); + /* Make sure the host task fpsimd state is visible to hyp: */ ret = kvm_share_hyp(fpsimd, fpsimd + 1); - if (!ret) - vcpu->arch.host_fpsimd_state = kern_hyp_va(fpsimd); + if (ret) + return ret; + + vcpu->arch.host_fpsimd_state = kern_hyp_va(fpsimd); + + /* + * We need to keep current's task_struct pinned until its data has been + * unshared with the hypervisor to make sure it is not re-used by the + * kernel and donated to someone else while already shared -- see + * kvm_vcpu_unshare_task_fp() for the matching put_task_struct(). + */ + if (is_protected_kvm_enabled()) { + get_task_struct(current); + vcpu->arch.parent_task = current; + } - return ret; + return 0; } /* |