[PATCH v7 0/3] KVM: SVM: Flush cache only on CPUs running SEV guest
From: Zheyun Shen
Date: Mon Jan 27 2025 - 20:54:17 EST
Previous versions pointed out the problem of wbinvd_on_all_cpus() in SEV
and tried to maintain a cpumask to solve it. This version includes
further code cleanup.
Although dirty_mask is not maintained perfectly and may lead to wbinvd on
physical CPUs that are not running a SEV guest, it's still better than
wbinvd_on_all_cpus(). And vcpu migration is designed to be solved in
future work.
---
v6 -> v7:
- Fixed the writing oversight in sev_vcpu_load().
v5 -> v6:
- Replaced sev_get_wbinvd_dirty_mask() with the helper function
to_kvm_sev_info().
v4 -> v5:
- rebase to tip @ 15e2f65f2ecf .
- Added a commit to remove unnecessary calls to wbinvd().
- Changed some comments.
v3 -> v4:
- Added a wbinvd helper and export it to SEV.
- Changed the struct cpumask in kvm_sev_info into cpumask*, which should
be dynamically allocated and freed.
- Changed the time of recording the CPUs from pre_sev_run() to vcpu_load().
- Removed code of clearing the mask.
v2 -> v3:
- Replaced get_cpu() with parameter cpu in pre_sev_run().
v1 -> v2:
- Added sev_do_wbinvd() to wrap two operations.
- Used cpumask_test_and_clear_cpu() to avoid concurrent problems.
---
Zheyun Shen (3):
KVM: x86: Add a wbinvd helper
KVM: SVM: Remove wbinvd in sev_vm_destroy()
KVM: SVM: Flush cache only on CPUs running SEV guest
arch/x86/kvm/svm/sev.c | 36 +++++++++++++++++++++++++++---------
arch/x86/kvm/svm/svm.c | 2 ++
arch/x86/kvm/svm/svm.h | 5 ++++-
arch/x86/kvm/x86.c | 9 +++++++--
arch/x86/kvm/x86.h | 1 +
5 files changed, 41 insertions(+), 12 deletions(-)
--
2.34.1