From: Sean Christopherson <seanjc@google.com>
To: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Michael Roth <michael.roth@amd.com>,
x86@kernel.org, linux-kernel@vger.kernel.org,
kvm@vger.kernel.org, linux-efi@vger.kernel.org,
platform-driver-x86@vger.kernel.org, linux-coco@lists.linux.dev,
linux-mm@kvack.org, Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Joerg Roedel <jroedel@suse.de>,
"H. Peter Anvin" <hpa@zytor.com>,
Ard Biesheuvel <ardb@kernel.org>,
Paolo Bonzini <pbonzini@redhat.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
Jim Mattson <jmattson@google.com>,
Andy Lutomirski <luto@kernel.org>,
Dave Hansen <dave.hansen@linux.intel.com>,
Sergio Lopez <slp@redhat.com>, Peter Gonda <pgonda@google.com>,
Peter Zijlstra <peterz@infradead.org>,
Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>,
David Rientjes <rientjes@google.com>,
Dov Murik <dovmurik@linux.ibm.com>,
Tobin Feldman-Fitzthum <tobin@ibm.com>,
Borislav Petkov <bp@alien8.de>, Vlastimil Babka <vbabka@suse.cz>,
"Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>,
Andi Kleen <ak@linux.intel.com>,
"Dr . David Alan Gilbert" <dgilbert@redhat.com>,
brijesh.ksingh@gmail.com, tony.luck@intel.com,
marcorr@google.com, sathyanarayanan.kuppuswamy@linux.intel.com
Subject: Re: [PATCH v12 19/46] x86/kernel: Make the .bss..decrypted section shared in RMP table
Date: Thu, 16 Jun 2022 16:41:05 +0000 [thread overview]
Message-ID: <YqtdIf7OSivLxFL0@google.com> (raw)
In-Reply-To: <9abe9a71-242d-91d5-444a-b56c8b9b6d90@amd.com>
On Thu, Jun 16, 2022, Tom Lendacky wrote:
> On 6/14/22 14:52, Sean Christopherson wrote:
> > On Tue, Jun 14, 2022, Tom Lendacky wrote:
> > > On 6/14/22 11:13, Sean Christopherson wrote:
> > > > > > > This breaks SME on Rome and Milan when compiling with clang-13. I haven't been
> > > > > > > able to figure out exactly what goes wrong. printk isn't functional at this point,
> > > > > > > and interactive debug during boot on our test systems is beyond me. I can't even
> > > > > > > verify that the bug is specific to clang because the draconian build system for our
> > > > > > > test systems apparently is stuck pointing at gcc-4.9.
> > > > > > >
> > > > > > > I suspect the issue is related to relocation and/or encrypting memory, as skipping
> > > > > > > the call to early_snp_set_memory_shared() if SNP isn't active masks the issue.
> > > > > > > I've dug through the assembly and haven't spotted a smoking gun, e.g. no obvious
> > > > > > > use of absolute addresses.
> > > > > > >
> > > > > > > Forcing a VM through the same path doesn't fail. I can't test an SEV guest at the
> > > > > > > moment because INIT_EX is also broken.
> > > > > >
>
> >
> > > I'm not sure if there's a way to remove the jump table optimization for
> > > the arch/x86/coco/core.c file when retpolines aren't configured.
> >
> > And for post-boot I don't think we'd want to disable any such optimizations.
> >
> > A possibled "fix" would be to do what sme_encrypt_kernel() does and just query
> > sev_status directly. But even that works, the fragility of the boot code is
> > terrifying :-( I can't think of any clever solutions though.
>
> I worry that another use of cc_platform_has() could creep in at some point
> and cause the same issue. Not sure how bad it would be, performance-wise, to
> remove the jump table optimization for arch/x86/coco/core.c.
One thought would be to initialize "vendor" to a bogus value, disallow calls to
cc_set_vendor() until after the kernel as gotten to a safe point, and then WARN
(or panic?) if cc_platform_has() is called before "vendor" is explicitly set.
New calls can still get in, but they'll be much easier to detect and less likely
to escape initial testing.
diff --git a/arch/x86/coco/core.c b/arch/x86/coco/core.c
index 49b44f881484..803220cd34a6 100644
--- a/arch/x86/coco/core.c
+++ b/arch/x86/coco/core.c
@@ -13,7 +13,11 @@
#include <asm/coco.h>
#include <asm/processor.h>
-static enum cc_vendor vendor __ro_after_init;
+/*
+ * Initialize the vendor to garbage to detect usage of cc_platform_has() before
+ * the vendor has been set.
+ */
+static enum cc_vendor vendor = CC_NR_VENDORS __ro_after_init;
static u64 cc_mask __ro_after_init;
static bool intel_cc_platform_has(enum cc_attr attr)
@@ -90,7 +94,10 @@ bool cc_platform_has(enum cc_attr attr)
return intel_cc_platform_has(attr);
case CC_VENDOR_HYPERV:
return hyperv_cc_platform_has(attr);
+ case CC_VENDOR_NONE:
+ return false;
default:
+ WARN_ONCE(1, "blah blah blah");
return false;
}
}
diff --git a/arch/x86/include/asm/coco.h b/arch/x86/include/asm/coco.h
index 3d98c3a60d34..adfd2fbce7ac 100644
--- a/arch/x86/include/asm/coco.h
+++ b/arch/x86/include/asm/coco.h
@@ -9,6 +9,7 @@ enum cc_vendor {
CC_VENDOR_AMD,
CC_VENDOR_HYPERV,
CC_VENDOR_INTEL,
+ CC_NR_VENDORS,
};
void cc_set_vendor(enum cc_vendor v);
> I guess we can wait for Boris to get back and chime in.
>
> > diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
> > index bd4a34100ed0..5efab0d8e49d 100644
> > --- a/arch/x86/kernel/head64.c
> > +++ b/arch/x86/kernel/head64.c
> > @@ -127,7 +127,9 @@ static bool __head check_la57_support(unsigned long physaddr)
> > }
> > #endif
> >
> > -static unsigned long __head sme_postprocess_startup(struct boot_params *bp, pmdval_t *pmd)
> > +static unsigned long __head sme_postprocess_startup(struct boot_params *bp,
> > + pmdval_t *pmd,
> > + unsigned long physaddr)
>
> I noticed that you added the physaddr parameter but never use it...
Likely just garbage on my end, I was trying various ideas.
next prev parent reply other threads:[~2022-06-16 16:41 UTC|newest]
Thread overview: 129+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-07 21:33 [PATCH v12 00/46] Add AMD Secure Nested Paging (SEV-SNP) Guest Support Brijesh Singh
2022-03-07 21:33 ` [PATCH v12 01/46] KVM: SVM: Define sev_features and vmpl field in the VMSA Brijesh Singh
2022-04-08 9:09 ` [tip: x86/sev] KVM: SVM: Define sev_features and VMPL " tip-bot2 for Brijesh Singh
2022-03-07 21:33 ` [PATCH v12 02/46] KVM: SVM: Create a separate mapping for the SEV-ES save area Brijesh Singh
2022-04-05 18:27 ` [PATCH v12 2.1/46] " Brijesh Singh
2022-04-05 18:55 ` Borislav Petkov
2022-04-08 9:09 ` [tip: x86/sev] " tip-bot2 for Tom Lendacky
2022-03-07 21:33 ` [PATCH v12 03/46] KVM: SVM: Create a separate mapping for the GHCB " Brijesh Singh
2022-04-08 9:09 ` [tip: x86/sev] " tip-bot2 for Tom Lendacky
2022-03-07 21:33 ` [PATCH v12 04/46] KVM: SVM: Update the SEV-ES save area mapping Brijesh Singh
2022-04-08 9:09 ` [tip: x86/sev] " tip-bot2 for Tom Lendacky
2022-03-07 21:33 ` [PATCH v12 05/46] x86/boot: Introduce helpers for MSR reads/writes Brijesh Singh
2022-04-08 9:09 ` [tip: x86/sev] " tip-bot2 for Michael Roth
2022-03-07 21:33 ` [PATCH v12 06/46] x86/boot: Use MSR read/write helpers instead of inline assembly Brijesh Singh
2022-04-08 9:09 ` [tip: x86/sev] " tip-bot2 for Michael Roth
2022-03-07 21:33 ` [PATCH v12 07/46] x86/compressed/64: Detect/setup SEV/SME features earlier in boot Brijesh Singh
2022-04-08 9:09 ` [tip: x86/sev] x86/compressed/64: Detect/setup SEV/SME features earlier during boot tip-bot2 for Michael Roth
2022-03-07 21:33 ` [PATCH v12 08/46] x86/sev: Detect/setup SEV/SME features earlier in boot Brijesh Singh
2022-04-08 9:09 ` [tip: x86/sev] " tip-bot2 for Michael Roth
2022-03-07 21:33 ` [PATCH v12 09/46] x86/mm: Extend cc_attr to include AMD SEV-SNP Brijesh Singh
2022-04-08 9:09 ` [tip: x86/sev] " tip-bot2 for Brijesh Singh
2022-03-07 21:33 ` [PATCH v12 10/46] x86/sev: Define the Linux specific guest termination reasons Brijesh Singh
2022-04-08 9:09 ` [tip: x86/sev] x86/sev: Define the Linux-specific " tip-bot2 for Brijesh Singh
2022-03-07 21:33 ` [PATCH v12 11/46] x86/sev: Save the negotiated GHCB version Brijesh Singh
2022-04-08 9:09 ` [tip: x86/sev] " tip-bot2 for Brijesh Singh
2022-03-07 21:33 ` [PATCH v12 12/46] x86/sev: Check SEV-SNP features support Brijesh Singh
2022-04-08 9:09 ` [tip: x86/sev] " tip-bot2 for Brijesh Singh
2022-03-07 21:33 ` [PATCH v12 13/46] x86/sev: Add a helper for the PVALIDATE instruction Brijesh Singh
2022-04-08 9:09 ` [tip: x86/sev] " tip-bot2 for Brijesh Singh
2022-03-07 21:33 ` [PATCH v12 14/46] x86/sev: Check the vmpl level Brijesh Singh
2022-04-08 9:09 ` [tip: x86/sev] x86/sev: Check the VMPL level tip-bot2 for Brijesh Singh
2022-03-07 21:33 ` [PATCH v12 15/46] x86/compressed: Add helper for validating pages in the decompression stage Brijesh Singh
2022-04-08 9:09 ` [tip: x86/sev] " tip-bot2 for Brijesh Singh
2022-03-07 21:33 ` [PATCH v12 16/46] x86/compressed: Register GHCB memory when SEV-SNP is active Brijesh Singh
2022-04-08 9:09 ` [tip: x86/sev] " tip-bot2 for Brijesh Singh
2022-03-07 21:33 ` [PATCH v12 17/46] x86/sev: " Brijesh Singh
2022-04-08 9:09 ` [tip: x86/sev] " tip-bot2 for Brijesh Singh
2022-03-07 21:33 ` [PATCH v12 18/46] x86/sev: Add helper for validating pages in early enc attribute changes Brijesh Singh
2022-04-08 9:09 ` [tip: x86/sev] " tip-bot2 for Brijesh Singh
2022-03-07 21:33 ` [PATCH v12 19/46] x86/kernel: Make the .bss..decrypted section shared in RMP table Brijesh Singh
2022-04-08 9:09 ` [tip: x86/sev] x86/kernel: Mark the .bss..decrypted section as shared in the " tip-bot2 for Brijesh Singh
2022-06-14 0:46 ` [PATCH v12 19/46] x86/kernel: Make the .bss..decrypted section shared in " Sean Christopherson
2022-06-14 15:43 ` Sean Christopherson
2022-06-14 16:01 ` Tom Lendacky
2022-06-14 16:13 ` Sean Christopherson
2022-06-14 19:00 ` Tom Lendacky
2022-06-14 19:52 ` Sean Christopherson
2022-06-16 16:17 ` Tom Lendacky
2022-06-16 16:41 ` Sean Christopherson [this message]
2022-07-01 16:51 ` Borislav Petkov
2022-07-07 20:43 ` Sean Christopherson
2022-03-07 21:33 ` [PATCH v12 20/46] x86/kernel: Validate ROM memory before accessing when SEV-SNP is active Brijesh Singh
2022-04-08 9:09 ` [tip: x86/sev] " tip-bot2 for Brijesh Singh
2022-03-07 21:33 ` [PATCH v12 21/46] x86/mm: Validate memory when changing the C-bit Brijesh Singh
2022-04-08 9:09 ` [tip: x86/sev] " tip-bot2 for Brijesh Singh
2022-03-07 21:33 ` [PATCH v12 22/46] x86/sev: Use SEV-SNP AP creation to start secondary CPUs Brijesh Singh
2022-04-05 0:24 ` Sean Christopherson
2022-04-05 16:20 ` Brijesh Singh
2022-04-05 19:41 ` Sean Christopherson
2022-04-08 9:09 ` [tip: x86/sev] " tip-bot2 for Tom Lendacky
2022-03-07 21:33 ` [PATCH v12 23/46] x86/head/64: Re-enable stack protection Brijesh Singh
2022-04-08 9:08 ` [tip: x86/sev] " tip-bot2 for Michael Roth
2022-03-07 21:33 ` [PATCH v12 24/46] x86/compressed/acpi: Move EFI detection to helper Brijesh Singh
2022-04-08 9:08 ` [tip: x86/sev] " tip-bot2 for Michael Roth
2022-03-07 21:33 ` [PATCH v12 25/46] x86/compressed/acpi: Move EFI system table lookup " Brijesh Singh
2022-04-08 9:08 ` [tip: x86/sev] " tip-bot2 for Michael Roth
2022-03-07 21:33 ` [PATCH v12 26/46] x86/compressed/acpi: Move EFI config " Brijesh Singh
2022-04-08 9:08 ` [tip: x86/sev] " tip-bot2 for Michael Roth
2022-03-07 21:33 ` [PATCH v12 27/46] x86/compressed/acpi: Move EFI vendor " Brijesh Singh
2022-04-08 9:08 ` [tip: x86/sev] " tip-bot2 for Michael Roth
2022-03-07 21:33 ` [PATCH v12 28/46] x86/compressed/acpi: Move EFI kexec handling into common code Brijesh Singh
2022-04-08 9:08 ` [tip: x86/sev] " tip-bot2 for Michael Roth
2022-03-07 21:33 ` [PATCH v12 29/46] x86/boot: Add Confidential Computing type to setup_data Brijesh Singh
2022-04-06 21:19 ` Thomas Gleixner
2022-04-07 14:47 ` Borislav Petkov
2022-04-07 14:57 ` Brijesh Singh
2022-07-17 5:08 ` H. Peter Anvin
2022-04-08 9:08 ` [tip: x86/sev] " tip-bot2 for Brijesh Singh
2022-03-07 21:33 ` [PATCH v12 30/46] KVM: x86: Move lookup of indexed CPUID leafs to helper Brijesh Singh
2022-04-08 9:08 ` [tip: x86/sev] " tip-bot2 for Michael Roth
2022-03-07 21:33 ` [PATCH v12 31/46] x86/sev: Move MSR-based VMGEXITs for CPUID " Brijesh Singh
2022-04-08 9:08 ` [tip: x86/sev] " tip-bot2 for Michael Roth
2022-03-07 21:33 ` [PATCH v12 32/46] x86/compressed/64: Add support for SEV-SNP CPUID table in #VC handlers Brijesh Singh
2022-03-10 14:51 ` Peter Gonda
2022-03-10 21:25 ` Michael Roth
2022-03-11 17:06 ` Joerg Roedel
2022-03-14 17:34 ` Peter Gonda
2022-03-17 13:11 ` Boris Petkov
2022-03-17 20:20 ` Peter Gonda
2022-04-08 9:08 ` [tip: x86/sev] " tip-bot2 for Michael Roth
2022-03-07 21:33 ` [PATCH v12 33/46] x86/boot: Add a pointer to Confidential Computing blob in bootparams Brijesh Singh
2022-04-08 9:08 ` [tip: x86/sev] " tip-bot2 for Michael Roth
2022-03-07 21:33 ` [PATCH v12 34/46] x86/compressed: Add SEV-SNP feature detection/setup Brijesh Singh
2022-04-08 9:08 ` [tip: x86/sev] " tip-bot2 for Michael Roth
2022-03-07 21:33 ` [PATCH v12 35/46] x86/compressed: Use firmware-validated CPUID leaves for SEV-SNP guests Brijesh Singh
2022-04-08 9:08 ` [tip: x86/sev] " tip-bot2 for Michael Roth
2022-03-07 21:33 ` [PATCH v12 36/46] x86/compressed: Export and rename add_identity_map() Brijesh Singh
2022-04-08 9:08 ` [tip: x86/sev] " tip-bot2 for Michael Roth
2022-03-07 21:33 ` [PATCH v12 37/46] x86/compressed/64: Add identity mapping for Confidential Computing blob Brijesh Singh
2022-04-08 9:08 ` [tip: x86/sev] " tip-bot2 for Michael Roth
2022-03-07 21:33 ` [PATCH v12 38/46] x86/sev: Add SEV-SNP feature detection/setup Brijesh Singh
2022-04-08 9:08 ` [tip: x86/sev] " tip-bot2 for Michael Roth
2022-03-07 21:33 ` [PATCH v12 39/46] x86/sev: Use firmware-validated CPUID for SEV-SNP guests Brijesh Singh
2022-04-08 9:08 ` [tip: x86/sev] " tip-bot2 for Michael Roth
2022-03-07 21:33 ` [PATCH v12 40/46] x86/sev: add sev=debug cmdline option to dump SNP CPUID table Brijesh Singh
2022-03-25 9:24 ` Borislav Petkov
2022-04-08 9:08 ` [tip: x86/sev] x86/sev: Add a sev= cmdline option tip-bot2 for Michael Roth
2022-03-07 21:33 ` [PATCH v12 41/46] x86/sev: Provide support for SNP guest request NAEs Brijesh Singh
2022-04-08 9:08 ` [tip: x86/sev] " tip-bot2 for Brijesh Singh
2022-03-07 21:33 ` [PATCH v12 42/46] x86/sev: Register SEV-SNP guest request platform device Brijesh Singh
2022-04-08 9:08 ` [tip: x86/sev] " tip-bot2 for Brijesh Singh
2022-03-07 21:33 ` [PATCH v12 43/46] virt: Add SEV-SNP guest driver Brijesh Singh
2022-04-08 9:08 ` [tip: x86/sev] " tip-bot2 for Brijesh Singh
2022-04-18 16:42 ` Dionna Amalie Glaze
2022-04-18 17:14 ` Borislav Petkov
2022-04-18 17:40 ` Tom Lendacky
2022-04-18 21:18 ` Borislav Petkov
2022-08-24 18:01 ` [PATCH v12 43/46] " Dionna Amalie Glaze
2022-08-24 19:28 ` Peter Gonda
2022-08-25 18:54 ` Tom Lendacky
2022-08-25 20:09 ` Peter Gonda
2022-03-07 21:33 ` [PATCH v12 44/46] virt: sevguest: Add support to derive key Brijesh Singh
2022-04-08 9:08 ` [tip: x86/sev] " tip-bot2 for Brijesh Singh
2022-03-07 21:33 ` [PATCH v12 45/46] virt: sevguest: Add support to get extended report Brijesh Singh
2022-04-08 9:08 ` [tip: x86/sev] " tip-bot2 for Brijesh Singh
2022-03-07 21:33 ` [PATCH v12 46/46] virt: sevguest: Add documentation for SEV-SNP CPUID Enforcement Brijesh Singh
2022-03-14 15:37 ` Peter Gonda
2022-04-08 9:08 ` [tip: x86/sev] " tip-bot2 for Michael Roth
2022-03-07 21:53 ` [PATCH v12 43.1/46] virt: Add SEV-SNP guest driver Brijesh Singh
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