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Peter Anvin" , Ard Biesheuvel , Paolo Bonzini , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Andy Lutomirski , Dave Hansen , Sergio Lopez , Peter Gonda , Peter Zijlstra , Srinivas Pandruvada , David Rientjes , Dov Murik , Tobin Feldman-Fitzthum , Borislav Petkov , Michael Roth , Vlastimil Babka , "Kirill A . Shutemov" , Andi Kleen , tony.luck@intel.com, sathyanarayanan.kuppuswamy@linux.intel.com Content-Type: text/plain; charset="UTF-8" X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: D591850000B0 X-Stat-Signature: t77ubx6j3j59bw8c6hqttw4u6kh7rwyk Authentication-Results: imf04.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=kffc8Bs2; dmarc=pass (policy=reject) header.from=google.com; spf=pass (imf04.hostedemail.com: domain of marcorr@google.com designates 209.85.161.54 as permitted sender) smtp.mailfrom=marcorr@google.com X-HE-Tag: 1632430512-568287 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Thu, Sep 23, 2021 at 1:44 PM Brijesh Singh wrote: > > > On 9/23/21 2:17 PM, Marc Orr wrote: > > >>>> + > >>>> +struct page *snp_safe_alloc_page(struct kvm_vcpu *vcpu) > >>>> +{ > >>>> + unsigned long pfn; > >>>> + struct page *p; > >>>> + > >>>> + if (!cpu_feature_enabled(X86_FEATURE_SEV_SNP)) > >>>> + return alloc_page(GFP_KERNEL_ACCOUNT | __GFP_ZERO); > > Continuing my other comment, above: if we introduce a > > `snp_globally_enabled` var, we could use that here, rather than > > `cpu_feature_enabled(X86_FEATURE_SEV_SNP)`. > > > Maybe I am missing something, what is wrong with > cpu_feature_enabled(...) check ? It's same as creating a global > variable. The feature enabled bit is not set if the said is not > enabled. See the patch #3 [1] in this series. > > [1] > https://lore.kernel.org/linux-mm/YUN+L0dlFMbC3bd4@zn.tnic/T/#m2ac1242b33abfcd0d9fb22a89f4c103eacf67ea7 > > thanks You are right. Patch #3 does exactly what I was asking for in `snp_rmptable_init()`. Thanks!