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Tue, 5 Nov 2019 12:37:41 +1100 (AEDT) Received: by mail-qt1-x843.google.com with SMTP id l24so8764405qtp.10 for ; Mon, 04 Nov 2019 17:37:41 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=intel-com.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=W2L5Wt9vAPwi2DADGCrJo4/gpgrXJ/vHj0hp5uT1/6w=; b=qw3wPwnJQEPIsA7f/w0mDIf51WQSqHZtNBtHkQ+a6qdpUzMOEXt/OAxm9io3JhbfP6 vTne7iEDoazWXW5xBbihS1O0cnamLcICRUtMB42yA1LqBFurawpARa+pI/loQ7TZozCS muNK+/gOteA/6DrrAtwCv6qzAGFDNLrT4lxpVufIgKeSiYXHaqk5RVXbSWJ1ueKtHuiv oOY+F9gg4Xa4vW+/ls61g41NWotER0Buor3x0J0NDaC4S7Hry/ZYzIQIeOoT7pjyK/9n KejzKKo5jxtmx28oPc0/OrVyt4Yy1MBj0AZXomNXumyf6TV3OJA/dy91Qa7O4iQ+cyCX +Lwg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=W2L5Wt9vAPwi2DADGCrJo4/gpgrXJ/vHj0hp5uT1/6w=; 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charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Mailman-Approved-At: Tue, 05 Nov 2019 13:26:42 +1100 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-hyperv@vger.kernel.org, Michal Hocko , =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= , KVM list , Pavel Tatashin , KarimAllah Ahmed , Dave Hansen , Alexander Duyck , Michal Hocko , Linux MM , Paul Mackerras , "H. Peter Anvin" , Wanpeng Li , Alexander Duyck , "K. Y. Srinivasan" , Thomas Gleixner , Kees Cook , devel@driverdev.osuosl.org, Stefano Stabellini , Stephen Hemminger , "Aneesh Kumar K.V" , Joerg Roedel , X86 ML , YueHaibing , "Matthew Wilcox \(Oracle\)" , Mike Rapoport , Peter Zijlstra , Ingo Molnar , Vlastimil Babka , Anthony Yznaga , Oscar Salvador , "Isaac J. Manjarres" , Matt Sickler , Juergen Gross , Anshuman Khandual , Haiyang Zhang , Sasha Levin , kvm-ppc@vger.kernel.org, Qian Cai , Alex Williamson , Mike Rapoport , Borislav Petkov , Nicholas Piggin , Andy Lutomirski , xen-devel , Boris Ostrovsky , Vitaly Kuznetsov , Allison Randal , Jim Mattson , Mel Gorman , Cornelia Huck , Pavel Tatashin , Linux Kernel Mailing List , Sean Christopherson , Johannes Weiner , Paolo Bonzini , Andrew Morton , linuxppc-dev Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Thu, Oct 24, 2019 at 5:10 AM David Hildenbrand wrote: > > Right now, ZONE_DEVICE memory is always set PG_reserved. We want to > change that. > > KVM has this weird use case that you can map anything from /dev/mem > into the guest. pfn_valid() is not a reliable check whether the memmap > was initialized and can be touched. pfn_to_online_page() makes sure > that we have an initialized memmap (and don't have ZONE_DEVICE memory). > > Rewrite kvm_is_mmio_pfn() to make sure the function produces the > same result once we stop setting ZONE_DEVICE pages PG_reserved. > > Cc: Paolo Bonzini > Cc: "Radim Kr=C4=8Dm=C3=A1=C5=99" > Cc: Sean Christopherson > Cc: Vitaly Kuznetsov > Cc: Wanpeng Li > Cc: Jim Mattson > Cc: Joerg Roedel > Cc: Thomas Gleixner > Cc: Ingo Molnar > Cc: Borislav Petkov > Cc: "H. Peter Anvin" > Cc: KarimAllah Ahmed > Cc: Michal Hocko > Cc: Dan Williams > Signed-off-by: David Hildenbrand > --- > arch/x86/kvm/mmu.c | 29 +++++++++++++++++------------ > 1 file changed, 17 insertions(+), 12 deletions(-) > > diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c > index 24c23c66b226..f03089a336de 100644 > --- a/arch/x86/kvm/mmu.c > +++ b/arch/x86/kvm/mmu.c > @@ -2962,20 +2962,25 @@ static bool mmu_need_write_protect(struct kvm_vcp= u *vcpu, gfn_t gfn, > > static bool kvm_is_mmio_pfn(kvm_pfn_t pfn) > { > + struct page *page =3D pfn_to_online_page(pfn); > + > + /* > + * ZONE_DEVICE pages are never online. Online pages that are rese= rved > + * either indicate the zero page or MMIO pages. > + */ > + if (page) > + return !is_zero_pfn(pfn) && PageReserved(pfn_to_page(pfn)= ); > + > + /* > + * Anything with a valid (but not online) memmap could be ZONE_DE= VICE. > + * Treat only UC/UC-/WC pages as MMIO. You might clarify that ZONE_DEVICE pages that belong to WB cacheable pmem have the correct memtype established by devm_memremap_pages(). Other than that, feel free to add: Reviewed-by: Dan Williams