From: Tom Lendacky <thomas.lendacky@amd.com>
To: Boris Ostrovsky <boris.ostrovsky@oracle.com>,
linux-arch@vger.kernel.org, linux-efi@vger.kernel.org,
kvm@vger.kernel.org, linux-doc@vger.kernel.org, x86@kernel.org,
kexec@lists.infradead.org, linux-kernel@vger.kernel.org,
kasan-dev@googlegroups.com, linux-mm@kvack.org,
iommu@lists.linux-foundation.org
Cc: "Brijesh Singh" <brijesh.singh@amd.com>,
"Toshimitsu Kani" <toshi.kani@hpe.com>,
"Radim Krčmář" <rkrcmar@redhat.com>,
"Matt Fleming" <matt@codeblueprint.co.uk>,
"Alexander Potapenko" <glider@google.com>,
"H. Peter Anvin" <hpa@zytor.com>,
"Larry Woodman" <lwoodman@redhat.com>,
"Jonathan Corbet" <corbet@lwn.net>,
"Joerg Roedel" <joro@8bytes.org>,
"Michael S. Tsirkin" <mst@redhat.com>,
"Ingo Molnar" <mingo@redhat.com>,
"Andrey Ryabinin" <aryabinin@virtuozzo.com>,
"Dave Young" <dyoung@redhat.com>,
"Rik van Riel" <riel@redhat.com>, "Arnd Bergmann" <arnd@arndb.de>,
"Borislav Petkov" <bp@alien8.de>,
"Andy Lutomirski" <luto@kernel.org>,
"Thomas Gleixner" <tglx@linutronix.de>,
"Dmitry Vyukov" <dvyukov@google.com>,
"Juergen Gross" <jgross@suse.com>,
xen-devel <xen-devel@lists.xen.org>,
"Paolo Bonzini" <pbonzini@redhat.com>
Subject: Re: [PATCH v6 10/34] x86, x86/mm, x86/xen, olpc: Use __va() against just the physical address in cr3
Date: Thu, 8 Jun 2017 08:42:51 -0500 [thread overview]
Message-ID: <4a7376fb-abfc-8edd-42b7-38de461ac65e__22050.9422979832$1496929447$gmane$org@amd.com> (raw)
In-Reply-To: <b15e8924-4069-b5fa-adb2-86c164b1dd36@oracle.com>
On 6/7/2017 5:06 PM, Boris Ostrovsky wrote:
> On 06/07/2017 03:14 PM, Tom Lendacky wrote:
>> The cr3 register entry can contain the SME encryption bit that indicates
>> the PGD is encrypted. The encryption bit should not be used when creating
>> a virtual address for the PGD table.
>>
>> Create a new function, read_cr3_pa(), that will extract the physical
>> address from the cr3 register. This function is then used where a virtual
>> address of the PGD needs to be created/used from the cr3 register.
>>
>> Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
>> ---
>> arch/x86/include/asm/special_insns.h | 9 +++++++++
>> arch/x86/kernel/head64.c | 2 +-
>> arch/x86/mm/fault.c | 10 +++++-----
>> arch/x86/mm/ioremap.c | 2 +-
>> arch/x86/platform/olpc/olpc-xo1-pm.c | 2 +-
>> arch/x86/power/hibernate_64.c | 2 +-
>> arch/x86/xen/mmu_pv.c | 6 +++---
>> 7 files changed, 21 insertions(+), 12 deletions(-)
>>
...
>> diff --git a/arch/x86/xen/mmu_pv.c b/arch/x86/xen/mmu_pv.c
>> index 1f386d7..2dc5243 100644
>> --- a/arch/x86/xen/mmu_pv.c
>> +++ b/arch/x86/xen/mmu_pv.c
>> @@ -2022,7 +2022,7 @@ static phys_addr_t __init xen_early_virt_to_phys(unsigned long vaddr)
>> pmd_t pmd;
>> pte_t pte;
>>
>> - pa = read_cr3();
>> + pa = read_cr3_pa();
>> pgd = native_make_pgd(xen_read_phys_ulong(pa + pgd_index(vaddr) *
>> sizeof(pgd)));
>> if (!pgd_present(pgd))
>> @@ -2102,7 +2102,7 @@ void __init xen_relocate_p2m(void)
>> pt_phys = pmd_phys + PFN_PHYS(n_pmd);
>> p2m_pfn = PFN_DOWN(pt_phys) + n_pt;
>>
>> - pgd = __va(read_cr3());
>> + pgd = __va(read_cr3_pa());
>> new_p2m = (unsigned long *)(2 * PGDIR_SIZE);
>> idx_p4d = 0;
>> save_pud = n_pud;
>> @@ -2209,7 +2209,7 @@ static void __init xen_write_cr3_init(unsigned long cr3)
>> {
>> unsigned long pfn = PFN_DOWN(__pa(swapper_pg_dir));
>>
>> - BUG_ON(read_cr3() != __pa(initial_page_table));
>> + BUG_ON(read_cr3_pa() != __pa(initial_page_table));
>> BUG_ON(cr3 != __pa(swapper_pg_dir));
>>
>> /*
>
>
> (Please copy Xen maintainers when modifying xen-related files.)
Sorry about that, missed adding the Xen maintainers when I added this
change.
>
> Given that page tables for Xen PV guests are controlled by the
> hypervisor I don't think this change (although harmless) is necessary.
I can back this change out if the Xen maintainers think that's best.
> What may be needed is making sure X86_FEATURE_SME is not set for PV guests.
And that may be something that Xen will need to control through either
CPUID or MSR support for the PV guests.
Thanks,
Tom
>
> -boris
>
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Xen-devel@lists.xen.org
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next prev parent reply other threads:[~2017-06-08 13:42 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20170607191309.28645.15241.stgit@tlendack-t1.amdoffice.net>
[not found] ` <20170607191453.28645.92256.stgit@tlendack-t1.amdoffice.net>
2017-06-07 22:06 ` [PATCH v6 10/34] x86, x86/mm, x86/xen, olpc: Use __va() against just the physical address in cr3 Boris Ostrovsky
[not found] ` <b15e8924-4069-b5fa-adb2-86c164b1dd36@oracle.com>
2017-06-08 13:42 ` Tom Lendacky [this message]
[not found] ` <4a7376fb-abfc-8edd-42b7-38de461ac65e@amd.com>
2017-06-08 20:51 ` Boris Ostrovsky
[not found] ` <67fe69ac-a213-8de3-db28-0e54bba95127@oracle.com>
2017-06-08 21:02 ` Tom Lendacky
[not found] ` <fcb196c8-f1eb-a38c-336c-7bd3929b029e@amd.com>
2017-06-08 21:17 ` Boris Ostrovsky
[not found] ` <12c7e511-996d-cf60-3a3b-0be7b41bd85b@oracle.com>
2017-06-08 22:01 ` Andrew Cooper
[not found] ` <d37917b1-8e49-e8a8-b9ac-59491331640f@citrix.com>
2017-06-09 18:36 ` Tom Lendacky
[not found] ` <9725c503-2e33-2365-87f5-f017e1cbe9b6@amd.com>
2017-06-09 18:43 ` Boris Ostrovsky
[not found] ` <8e8eac45-95be-f1b5-6f44-f131d275f7bc@oracle.com>
2017-06-09 18:54 ` Andrew Cooper
2017-06-09 18:59 ` Tom Lendacky
[not found] ` <33f20df0-bf71-bd9d-7a7e-4fb5e8793400@amd.com>
2017-06-09 19:42 ` Boris Ostrovsky
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