From: Demi Marie Obenour <demi@invisiblethingslab.com>
To: Jan Beulich <jbeulich@suse.com>
Cc: linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org,
xen-devel@lists.xenproject.org, Ard Biesheuvel <ardb@kernel.org>,
Juergen Gross <jgross@suse.com>,
Stefano Stabellini <sstabellini@kernel.org>,
Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Subject: Re: [PATCH] Add support for ESRT loading under Xen
Date: Fri, 26 Aug 2022 14:01:44 -0400 [thread overview]
Message-ID: <YwkKiFIKHG4IcCmH@itl-email> (raw)
In-Reply-To: <c2a22672-b9dd-7aa4-b61e-ccb0faaa3b01@suse.com>
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On Fri, Aug 26, 2022 at 09:53:29AM +0200, Jan Beulich wrote:
> On 25.08.2022 23:52, Demi Marie Obenour wrote:
> > @@ -40,6 +41,38 @@
> >
> > #define efi_data(op) (op.u.efi_runtime_call)
> >
> > +static_assert(XEN_PAGE_SHIFT == EFI_PAGE_SHIFT,
> > + "Mismatch between EFI_PAGE_SHIFT and XEN_PAGE_SHIFT");
> > +
> > +bool xen_efi_mem_desc_lookup(u64 phys_addr, efi_memory_desc_t *md)
> > +{
> > + struct xen_platform_op op = {
> > + .cmd = XENPF_firmware_info,
> > + .u.firmware_info = {
> > + .type = XEN_FW_EFI_INFO,
> > + .index = XEN_FW_EFI_MEM_INFO,
> > + .u.efi_info.mem.addr = phys_addr,
> > + .u.efi_info.mem.size = ((u64)-1ULL) - phys_addr,
> > + }
> > + };
> > + union xenpf_efi_info *info = &op.u.firmware_info.u.efi_info;
> > + int rc;
> > +
> > + memset(md, 0, sizeof(*md)); /* initialize md even on failure */
> > + rc = HYPERVISOR_platform_op(&op);
> > + if (rc) {
> > + pr_warn("Could not obtain information on address %llu from Xen: "
> > + "error %d\n", phys_addr, rc);
> > + return false;
> > + }
> > +
> > + md->attribute = info->mem.attr;
> > + md->type = info->mem.type;
> > + md->num_pages = info->mem.size >> XEN_PAGE_SHIFT;
> > + md->phys_addr = info->mem.addr;
>
> As indicated in reply to your patch changing XEN_FW_EFI_MEM_INFO in
> the hypervisor: While this may fit the ESRT purpose, the address you
> return here is not necessarily the start of the region, and hence
> this function is not a general Xen replacement for the non-Xen
> function. Therefore I think it also shouldn't give the impression of
> doing so.
Is this just a matter of renaming the function? Is it possible to
implement the original function with the current hypervisor?
--
Sincerely,
Demi Marie Obenour (she/her/hers)
Invisible Things Lab
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next prev parent reply other threads:[~2022-08-26 18:01 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-25 21:52 [PATCH] Add support for ESRT loading under Xen Demi Marie Obenour
2022-08-26 7:53 ` Jan Beulich
2022-08-26 18:01 ` Demi Marie Obenour [this message]
2022-09-06 6:49 ` Jan Beulich
2022-09-13 13:36 ` Demi Marie Obenour
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