On Tue, May 06, 2025 at 04:37:22PM +0800, Binbin Wu wrote:
>
>
> On 4/24/2025 11:05 AM, Yan Zhao wrote:
> > From: Xiaoyao Li <xiaoyao.li@xxxxxxxxx>
> >
> > After a guest page is removed from the S-EPT, KVM calls
> > tdh_phymem_page_wbinvd_hkid() to execute WBINVD on the page using the TD's
> > keyID.
> >
> > Add a helper function that takes level information to perform WBINVD on a
> > huge page.
> >
> > [Yan: split patch, added a helper, rebased to use struct page]
> > Signed-off-by: Xiaoyao Li <xiaoyao.li@xxxxxxxxx>
> > Signed-off-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
> > Signed-off-by: Yan Zhao <yan.y.zhao@xxxxxxxxx>
> > ---
> > arch/x86/kvm/vmx/tdx.c | 24 +++++++++++++++++++-----
> > 1 file changed, 19 insertions(+), 5 deletions(-)
> >
> > diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
> > index 69f3140928b5..355b21fc169f 100644
> > --- a/arch/x86/kvm/vmx/tdx.c
> > +++ b/arch/x86/kvm/vmx/tdx.c
> > @@ -1586,6 +1586,23 @@ int tdx_sept_set_private_spte(struct kvm *kvm, gfn_t gfn,
> > return tdx_mem_page_record_premap_cnt(kvm, level);
> > }
> > +static inline u64 tdx_wbinvd_page(struct kvm *kvm, u64 hkid, struct page *page, int level)
> > +{
> > + unsigned long nr = KVM_PAGES_PER_HPAGE(level);
> > + unsigned long idx = 0;
> > + u64 err;
> > +
> > + while (nr--) {
> > + err = tdh_phymem_page_wbinvd_hkid(hkid, nth_page(page, idx++));
> > +
> > + if (KVM_BUG_ON(err, kvm)) {
> > + pr_tdx_error(TDH_PHYMEM_PAGE_WBINVD, err);
> > + return err;
> > + }
> > + }
> > + return err;
> > +}
> > +
> > static int tdx_sept_drop_private_spte(struct kvm *kvm, gfn_t gfn,
> > enum pg_level level, struct page *page)
> > {
> > @@ -1625,12 +1642,9 @@ static int tdx_sept_drop_private_spte(struct kvm *kvm, gfn_t gfn,
> > return -EIO;
> > }
> > - err = tdh_phymem_page_wbinvd_hkid((u16)kvm_tdx->hkid, page);
> > -
> > - if (KVM_BUG_ON(err, kvm)) {
> > - pr_tdx_error(TDH_PHYMEM_PAGE_WBINVD, err);
> > + err = tdx_wbinvd_page(kvm, kvm_tdx->hkid, page, level);
> > + if (err)
>
> It can add unlikely() here.
> Also the err is not used after check, maybe it can be combined as:
>
> if (unlikely(tdx_wbinvd_page(kvm, kvm_tdx->hkid, page, level)))
> return -EIO;
That's better. Thanks!
> > return -EIO;
> > - }
> > tdx_clear_page(page, level);
> > tdx_unpin(kvm, page);
>
