From: Sathyanarayanan Kuppuswamy <sathyanarayanan.kuppuswamy@linux.intel.com>
To: Michael Kelley <mikelley@microsoft.com>,
hpa@zytor.com, kys@microsoft.com, haiyangz@microsoft.com,
wei.liu@kernel.org, decui@microsoft.com, luto@kernel.org,
peterz@infradead.org, davem@davemloft.net, edumazet@google.com,
kuba@kernel.org, pabeni@redhat.com, lpieralisi@kernel.org,
robh@kernel.org, kw@linux.com, bhelgaas@google.com,
arnd@arndb.de, hch@infradead.org, m.szyprowski@samsung.com,
robin.murphy@arm.com, thomas.lendacky@amd.com,
brijesh.singh@amd.com, tglx@linutronix.de, mingo@redhat.com,
bp@alien8.de, dave.hansen@linux.intel.com,
Tianyu.Lan@microsoft.com, kirill.shutemov@linux.intel.com,
ak@linux.intel.com, isaku.yamahata@intel.com,
dan.j.williams@intel.com, jane.chu@oracle.com, seanjc@google.com,
tony.luck@intel.com, x86@kernel.org,
linux-kernel@vger.kernel.org, linux-hyperv@vger.kernel.org,
netdev@vger.kernel.org, linux-pci@vger.kernel.org,
linux-arch@vger.kernel.org, iommu@lists.linux.dev
Subject: Re: [Patch v4 01/13] x86/ioapic: Gate decrypted mapping on cc_platform_has() attribute
Date: Tue, 6 Dec 2022 11:27:13 -0800 [thread overview]
Message-ID: <a531ff8a-79a2-f801-921b-0c83d3d44913@linux.intel.com> (raw)
In-Reply-To: <1669951831-4180-2-git-send-email-mikelley@microsoft.com>
On 12/1/22 7:30 PM, Michael Kelley wrote:
> Current code always maps the IO-APIC as shared (decrypted) in a
> confidential VM. But Hyper-V guest VMs on AMD SEV-SNP with vTOM
> enabled use a paravisor running in VMPL0 to emulate the IO-APIC.
> In such a case, the IO-APIC must be accessed as private (encrypted).
>
> Fix this by gating the IO-APIC decrypted mapping on a new
> cc_platform_has() attribute that a subsequent patch in the series
> will set only for guests using vTOM.
>
> Signed-off-by: Michael Kelley <mikelley@microsoft.com>
> Reviewed-by: Wei Liu <wei.liu@kernel.org>
> ---
Looks good to me.
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
> arch/x86/kernel/apic/io_apic.c | 3 ++-
> include/linux/cc_platform.h | 12 ++++++++++++
> 2 files changed, 14 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
> index a868b76..2b70e2e 100644
> --- a/arch/x86/kernel/apic/io_apic.c
> +++ b/arch/x86/kernel/apic/io_apic.c
> @@ -2686,7 +2686,8 @@ static void io_apic_set_fixmap(enum fixed_addresses idx, phys_addr_t phys)
> * Ensure fixmaps for IOAPIC MMIO respect memory encryption pgprot
> * bits, just like normal ioremap():
> */
> - flags = pgprot_decrypted(flags);
> + if (!cc_platform_has(CC_ATTR_ACCESS_IOAPIC_ENCRYPTED))
> + flags = pgprot_decrypted(flags);
>
> __set_fixmap(idx, phys, flags);
> }
> diff --git a/include/linux/cc_platform.h b/include/linux/cc_platform.h
> index cb0d6cd..7b63a7d 100644
> --- a/include/linux/cc_platform.h
> +++ b/include/linux/cc_platform.h
> @@ -90,6 +90,18 @@ enum cc_attr {
> * Examples include TDX Guest.
> */
> CC_ATTR_HOTPLUG_DISABLED,
> +
> + /**
> + * @CC_ATTR_ACCESS_IOAPIC_ENCRYPTED: Guest VM IO-APIC is encrypted
> + *
> + * The platform/OS is running as a guest/virtual machine with
> + * an IO-APIC that is emulated by a paravisor running in the
> + * guest VM context. As such, the IO-APIC is accessed in the
> + * encrypted portion of the guest physical address space.
> + *
> + * Examples include Hyper-V SEV-SNP guests using vTOM.
> + */
> + CC_ATTR_ACCESS_IOAPIC_ENCRYPTED,
> };
>
> #ifdef CONFIG_ARCH_HAS_CC_PLATFORM
--
Sathyanarayanan Kuppuswamy
Linux Kernel Developer
next prev parent reply other threads:[~2022-12-06 19:27 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-12-02 3:30 [Patch v4 00/13] Add PCI pass-thru support to Hyper-V Confidential VMs Michael Kelley
2022-12-02 3:30 ` [Patch v4 01/13] x86/ioapic: Gate decrypted mapping on cc_platform_has() attribute Michael Kelley
2022-12-06 19:22 ` Borislav Petkov
2022-12-06 19:54 ` Michael Kelley (LINUX)
2022-12-29 11:39 ` Borislav Petkov
2022-12-29 16:02 ` Michael Kelley (LINUX)
2022-12-06 19:27 ` Sathyanarayanan Kuppuswamy [this message]
2022-12-02 3:30 ` [Patch v4 02/13] x86/hyperv: Reorder code in prep for subsequent patch Michael Kelley
2022-12-02 3:30 ` [Patch v4 03/13] Drivers: hv: Explicitly request decrypted in vmap_pfn() calls Michael Kelley
2022-12-29 12:05 ` Borislav Petkov
2022-12-02 3:30 ` [Patch v4 04/13] x86/mm: Handle decryption/re-encryption of bss_decrypted consistently Michael Kelley
2022-12-29 12:17 ` Borislav Petkov
2022-12-29 16:25 ` Michael Kelley (LINUX)
2023-01-09 19:10 ` Borislav Petkov
2023-01-09 19:14 ` Michael Kelley (LINUX)
2022-12-29 16:54 ` Bjorn Helgaas
2022-12-29 17:12 ` Borislav Petkov
2022-12-02 3:30 ` [Patch v4 05/13] init: Call mem_encrypt_init() after Hyper-V hypercall init is done Michael Kelley
2022-12-06 19:37 ` Sathyanarayanan Kuppuswamy
2022-12-06 20:13 ` Michael Kelley (LINUX)
2022-12-06 20:30 ` Sathyanarayanan Kuppuswamy
2022-12-02 3:30 ` [Patch v4 06/13] x86/hyperv: Change vTOM handling to use standard coco mechanisms Michael Kelley
2023-01-09 16:38 ` Borislav Petkov
2023-01-09 17:37 ` Michael Kelley (LINUX)
2023-01-09 18:07 ` Borislav Petkov
2022-12-02 3:30 ` [Patch v4 07/13] swiotlb: Remove bounce buffer remapping for Hyper-V Michael Kelley
2023-01-09 18:05 ` Borislav Petkov
2022-12-02 3:30 ` [Patch v4 08/13] Drivers: hv: vmbus: Remove second mapping of VMBus monitor pages Michael Kelley
2022-12-02 3:30 ` [Patch v4 09/13] Drivers: hv: vmbus: Remove second way of mapping ring buffers Michael Kelley
2022-12-02 3:30 ` [Patch v4 10/13] hv_netvsc: Remove second mapping of send and recv buffers Michael Kelley
2022-12-02 3:30 ` [Patch v4 11/13] Drivers: hv: Don't remap addresses that are above shared_gpa_boundary Michael Kelley
2022-12-02 3:30 ` [Patch v4 12/13] PCI: hv: Add hypercalls to read/write MMIO space Michael Kelley
2022-12-02 3:30 ` [Patch v4 13/13] PCI: hv: Enable PCI pass-thru devices in Confidential VMs Michael Kelley
2023-01-09 18:47 ` [Patch v4 00/13] Add PCI pass-thru support to Hyper-V " Borislav Petkov
2023-01-09 19:35 ` Michael Kelley (LINUX)
2023-01-12 14:03 ` Wei Liu
2023-01-19 17:58 ` Dexuan Cui
2023-01-20 11:58 ` Borislav Petkov
2023-01-20 12:42 ` Wei Liu
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