Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.37 as permitted sender) client-ip=23.128.96.37;
MIME-Version: 1.0
References: <20231105163040.14904-1-pbonzini@redhat.com> <20231105163040.14904-26-pbonzini@redhat.com>
 <CA+EHjTxy6TWM3oBG0Q6v5090XTrs+M8_m5=6Z2E1P-HyTkrGWg@mail.gmail.com> <ZUkQjW-yMnLfD7XW@google.com>
In-Reply-To: <ZUkQjW-yMnLfD7XW@google.com>
From:   Fuad Tabba <tabba@google.com>
Date:   Mon, 6 Nov 2023 16:24:42 +0000
Message-ID: <CA+EHjTw8Om6DGatxGhLJHpUb4RY_ma1pidd=mYxTQseE7vDB4A@mail.gmail.com>
Subject: Re: [PATCH 25/34] KVM: selftests: Add helpers to convert guest memory
 b/w private and shared
To:     Sean Christopherson <seanjc@google.com>
Cc:     Paolo Bonzini <pbonzini@redhat.com>, Marc Zyngier <maz@kernel.org>,
        Oliver Upton <oliver.upton@linux.dev>,
        Huacai Chen <chenhuacai@kernel.org>,
        Michael Ellerman <mpe@ellerman.id.au>,
        Anup Patel <anup@brainfault.org>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        Palmer Dabbelt <palmer@dabbelt.com>,
        Albert Ou <aou@eecs.berkeley.edu>,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        Christian Brauner <brauner@kernel.org>,
        "Matthew Wilcox (Oracle)" <willy@infradead.org>,
        Andrew Morton <akpm@linux-foundation.org>, kvm@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev,
        linux-mips@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
        kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org,
        linux-fsdevel@vger.kernel.org, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org, Xiaoyao Li <xiaoyao.li@intel.com>,
        Xu Yilun <yilun.xu@intel.com>,
        Chao Peng <chao.p.peng@linux.intel.com>,
        Jarkko Sakkinen <jarkko@kernel.org>,
        Anish Moorthy <amoorthy@google.com>,
        David Matlack <dmatlack@google.com>,
        Yu Zhang <yu.c.zhang@linux.intel.com>,
        Isaku Yamahata <isaku.yamahata@intel.com>,
        =?UTF-8?B?TWlja2HDq2wgU2FsYcO8bg==?= <mic@digikod.net>,
        Vlastimil Babka <vbabka@suse.cz>,
        Vishal Annapurve <vannapurve@google.com>,
        Ackerley Tng <ackerleytng@google.com>,
        Maciej Szmigiero <mail@maciej.szmigiero.name>,
        David Hildenbrand <david@redhat.com>,
        Quentin Perret <qperret@google.com>,
        Michael Roth <michael.roth@amd.com>,
        Wang <wei.w.wang@intel.com>,
        Liam Merwick <liam.merwick@oracle.com>,
        Isaku Yamahata <isaku.yamahata@gmail.com>,
        "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Precedence: bulk

On Mon, Nov 6, 2023 at 4:13=E2=80=AFPM Sean Christopherson <seanjc@google.c=
om> wrote:
>
> On Mon, Nov 06, 2023, Fuad Tabba wrote:
> > On Sun, Nov 5, 2023 at 4:34=E2=80=AFPM Paolo Bonzini <pbonzini@redhat.c=
om> wrote:
> > > +void vm_guest_mem_fallocate(struct kvm_vm *vm, uint64_t base, uint64=
_t size,
> > > +                           bool punch_hole)
> > > +{
> > > +       const int mode =3D FALLOC_FL_KEEP_SIZE | (punch_hole ? FALLOC=
_FL_PUNCH_HOLE : 0);
> > > +       struct userspace_mem_region *region;
> > > +       uint64_t end =3D base + size;
> > > +       uint64_t gpa, len;
> > > +       off_t fd_offset;
> > > +       int ret;
> > > +
> > > +       for (gpa =3D base; gpa < end; gpa +=3D len) {
> > > +               uint64_t offset;
> > > +
> > > +               region =3D userspace_mem_region_find(vm, gpa, gpa);
> > > +               TEST_ASSERT(region && region->region.flags & KVM_MEM_=
GUEST_MEMFD,
> > > +                           "Private memory region not found for GPA =
0x%lx", gpa);
> > > +
> > > +               offset =3D (gpa - region->region.guest_phys_addr);
> >
> > nit: why the parentheses?
>
> I simply forgot to remove them when I changed the function to support spa=
nning
> multiple memslots, i.e. when the code went from this
>
>         fd_offset =3D region->region.gmem_offset +
>                     (gpa - region->region.guest_phys_addr);
>
> to what you see above.

I wasn't actually expecting an answer, but I literally _did_ ask for it :)

Thanks,
/fuad