Date:   Mon, 18 Jul 2022 11:57:13 +0100
From:   Vincent Donnefort <vdonnefort@google.com>
To:     Will Deacon <will@kernel.org>
Cc:     kvmarm@lists.cs.columbia.edu, Ard Biesheuvel <ardb@kernel.org>,
        Sean Christopherson <seanjc@google.com>,
        Alexandru Elisei <alexandru.elisei@arm.com>,
        Andy Lutomirski <luto@amacapital.net>,
        Catalin Marinas <catalin.marinas@arm.com>,
        James Morse <james.morse@arm.com>,
        Chao Peng <chao.p.peng@linux.intel.com>,
        Quentin Perret <qperret@google.com>,
        Suzuki K Poulose <suzuki.poulose@arm.com>,
        Michael Roth <michael.roth@amd.com>,
        Mark Rutland <mark.rutland@arm.com>,
        Fuad Tabba <tabba@google.com>,
        Oliver Upton <oliver.upton@linux.dev>,
        Marc Zyngier <maz@kernel.org>, kernel-team@android.com,
        kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v2 03/24] KVM: arm64: Add flags to struct hyp_page
Message-ID: <YtU8iX6tmTOpxvlJ@google.com>
References: <20220630135747.26983-1-will@kernel.org>
 <20220630135747.26983-4-will@kernel.org>
 <YtU74D9fcLCpHHwc@google.com>
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On Mon, Jul 18, 2022 at 11:54:24AM +0100, Vincent Donnefort wrote:
> On Thu, Jun 30, 2022 at 02:57:26PM +0100, Will Deacon wrote:
> > From: Quentin Perret <qperret@google.com>
> > 
> > Add a 'flags' field to struct hyp_page, and reduce the size of the order
> > field to u8 to avoid growing the struct size.
> > 
> > Signed-off-by: Quentin Perret <qperret@google.com>
> > Signed-off-by: Will Deacon <will@kernel.org>
> > ---
> >  arch/arm64/kvm/hyp/include/nvhe/gfp.h    |  6 +++---
> >  arch/arm64/kvm/hyp/include/nvhe/memory.h |  3 ++-
> >  arch/arm64/kvm/hyp/nvhe/page_alloc.c     | 14 +++++++-------
> >  3 files changed, 12 insertions(+), 11 deletions(-)
> > 
> > diff --git a/arch/arm64/kvm/hyp/include/nvhe/gfp.h b/arch/arm64/kvm/hyp/include/nvhe/gfp.h
> > index 0a048dc06a7d..9330b13075f8 100644
> > --- a/arch/arm64/kvm/hyp/include/nvhe/gfp.h
> > +++ b/arch/arm64/kvm/hyp/include/nvhe/gfp.h
> > @@ -7,7 +7,7 @@
> >  #include <nvhe/memory.h>
> >  #include <nvhe/spinlock.h>
> >  
> > -#define HYP_NO_ORDER	USHRT_MAX
> > +#define HYP_NO_ORDER	0xff
> 
> BUG_ON in hyp_page_ref_inc() might now need to test for 0xff/HYP_NO_ORDER
> instead of USHRT_MAX.

My bad, read to quickly, refcount/order... 

> 
> [...]