From: Brijesh Singh <brijesh.singh@amd.com>
To: x86@kernel.org, linux-kernel@vger.kernel.org,
kvm@vger.kernel.org, linux-coco@lists.linux.dev,
linux-mm@kvack.org, linux-crypto@vger.kernel.org
Cc: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Joerg Roedel <jroedel@suse.de>,
Tom Lendacky <thomas.lendacky@amd.com>,
"H. Peter Anvin" <hpa@zytor.com>,
Ard Biesheuvel <ardb@kernel.org>,
Paolo Bonzini <pbonzini@redhat.com>,
Sean Christopherson <seanjc@google.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
Wanpeng Li <wanpengli@tencent.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>,
tony.luck@intel.com, npmccallum@redhat.com,
Borislav Petkov <bp@suse.de>,
Brijesh Singh <brijesh.singh@amd.com>
Subject: [PATCH Part2 RFC v3 09/37] x86/fault: Add support to dump RMP entry on fault
Date: Wed, 2 Jun 2021 09:10:29 -0500 [thread overview]
Message-ID: <20210602141057.27107-10-brijesh.singh@amd.com> (raw)
In-Reply-To: <20210602141057.27107-1-brijesh.singh@amd.com>
When SEV-SNP is enabled globally, a write from the host goes through the
RMP check. If the hardware encounters the check failure, then it raises
the #PF (with RMP set). Dump the RMP table to help the debug.
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
---
arch/x86/mm/fault.c | 78 +++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 78 insertions(+)
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 2715240c757e..e6deedf27d78 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -19,6 +19,7 @@
#include <linux/uaccess.h> /* faulthandler_disabled() */
#include <linux/efi.h> /* efi_crash_gracefully_on_page_fault()*/
#include <linux/mm_types.h>
+#include <linux/sev.h> /* snp_lookup_page_in_rmptable() */
#include <asm/cpufeature.h> /* boot_cpu_has, ... */
#include <asm/traps.h> /* dotraplinkage, ... */
@@ -502,6 +503,80 @@ static void show_ldttss(const struct desc_ptr *gdt, const char *name, u16 index)
name, index, addr, (desc.limit0 | (desc.limit1 << 16)));
}
+static void dump_rmpentry(unsigned long address)
+{
+ struct rmpentry *e;
+ unsigned long pfn;
+ pgd_t *pgd;
+ pte_t *pte;
+ int level;
+
+ pgd = __va(read_cr3_pa());
+ pgd += pgd_index(address);
+
+ pte = lookup_address_in_pgd(pgd, address, &level);
+ if (unlikely(!pte))
+ return;
+
+ switch (level) {
+ case PG_LEVEL_4K: {
+ pfn = pte_pfn(*pte);
+ break;
+ }
+ case PG_LEVEL_2M: {
+ pfn = pmd_pfn(*(pmd_t *)pte);
+ break;
+ }
+ case PG_LEVEL_1G: {
+ pfn = pud_pfn(*(pud_t *)pte);
+ break;
+ }
+ case PG_LEVEL_512G: {
+ pfn = p4d_pfn(*(p4d_t *)pte);
+ break;
+ }
+ default:
+ return;
+ }
+
+ e = snp_lookup_page_in_rmptable(pfn_to_page(pfn), &level);
+ if (unlikely(!e))
+ return;
+
+ /*
+ * If the RMP entry at the faulting address was not assigned, then dump may
+ * not provide any useful debug information. Iterate through the entire 2MB
+ * region, and dump the RMP entries if one of the bit in the RMP entry is set.
+ */
+ if (rmpentry_assigned(e)) {
+ pr_alert("RMPEntry paddr 0x%lx [assigned=%d immutable=%d pagesize=%d gpa=0x%lx"
+ " asid=%d vmsa=%d validated=%d]\n", pfn << PAGE_SHIFT,
+ rmpentry_assigned(e), rmpentry_immutable(e), rmpentry_pagesize(e),
+ rmpentry_gpa(e), rmpentry_asid(e), rmpentry_vmsa(e),
+ rmpentry_validated(e));
+
+ pr_alert("RMPEntry paddr 0x%lx %016llx %016llx\n", pfn << PAGE_SHIFT,
+ e->high, e->low);
+ } else {
+ unsigned long pfn_end;
+
+ pfn = pfn & ~0x1ff;
+ pfn_end = pfn + PTRS_PER_PMD;
+
+ while (pfn < pfn_end) {
+ e = snp_lookup_page_in_rmptable(pfn_to_page(pfn), &level);
+
+ if (unlikely(!e))
+ return;
+
+ if (e->low || e->high)
+ pr_alert("RMPEntry paddr 0x%lx: %016llx %016llx\n",
+ pfn << PAGE_SHIFT, e->high, e->low);
+ pfn++;
+ }
+ }
+}
+
static void
show_fault_oops(struct pt_regs *regs, unsigned long error_code, unsigned long address)
{
@@ -578,6 +653,9 @@ show_fault_oops(struct pt_regs *regs, unsigned long error_code, unsigned long ad
}
dump_pagetable(address);
+
+ if (error_code & X86_PF_RMP)
+ dump_rmpentry(address);
}
static noinline void
--
2.17.1
next prev parent reply other threads:[~2021-06-02 14:11 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-02 14:10 [PATCH Part2 RFC v3 00/37] Add AMD Secure Nested Paging (SEV-SNP) Hypervisor Support Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 01/37] KVM: SVM: Add support to handle AP reset MSR protocol Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 02/37] KVM: SVM: Provide the Hypervisor Feature support VMGEXIT Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 03/37] x86/cpufeatures: Add SEV-SNP CPU feature Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 04/37] x86/sev: Add the host SEV-SNP initialization support Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 05/37] x86/sev: Add RMP entry lookup helpers Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 06/37] x86/sev: Add helper functions for RMPUPDATE and PSMASH instruction Brijesh Singh
2021-06-10 13:03 ` Dr. David Alan Gilbert
2021-06-02 14:10 ` [PATCH Part2 RFC v3 07/37] x86/sev: Split the physmap when adding the page in RMP table Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 08/37] x86/traps: Define RMP violation #PF error code Brijesh Singh
2021-06-02 14:10 ` Brijesh Singh [this message]
2021-06-02 14:10 ` [PATCH Part2 RFC v3 10/37] x86/fault: Add support to handle the RMP fault for user address Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 11/37] crypto:ccp: Define the SEV-SNP commands Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 12/37] crypto: ccp: Add support to initialize the AMD-SP for SEV-SNP Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 13/37] crypto: ccp: Shutdown SNP firmware on kexec Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 14/37] crypto:ccp: Provide APIs to issue SEV-SNP commands Brijesh Singh
2021-06-15 11:23 ` Dr. David Alan Gilbert
2021-06-02 14:10 ` [PATCH Part2 RFC v3 15/37] crypto: ccp: Handle the legacy TMR allocation when SNP is enabled Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 16/37] crypto: ccp: Handle the legacy SEV command " Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 17/37] KVM: SVM: make AVIC backing, VMSA and VMCB memory allocation SNP safe Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 18/37] KVM: SVM: Add initial SEV-SNP support Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 19/37] KVM: SVM: Add KVM_SNP_INIT command Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 20/37] KVM: SVM: Add KVM_SEV_SNP_LAUNCH_START command Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 21/37] KVM: SVM: Add KVM_SEV_SNP_LAUNCH_UPDATE command Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 22/37] KVM: SVM: Reclaim the guest pages when SEV-SNP VM terminates Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 23/37] KVM: SVM: Add KVM_SEV_SNP_LAUNCH_FINISH command Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 24/37] KVM: X86: Add kvm_x86_ops to get the max page level for the TDP Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 25/37] KVM: X86: Introduce kvm_mmu_map_tdp_page() for use by SEV Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 26/37] KVM: X86: Introduce kvm_mmu_get_tdp_walk() for SEV-SNP use Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 27/37] KVM: X86: Define new RMP check related #NPF error bits Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 28/37] KVM: X86: update page-fault trace to log the 64-bit error code Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 29/37] KVM: SVM: Add support to handle GHCB GPA register VMGEXIT Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 30/37] KVM: SVM: Add support to handle MSR based Page State Change VMGEXIT Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 31/37] KVM: SVM: Add support to handle " Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 32/37] KVM: Add arch hooks to track the host write to guest memory Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 33/37] KVM: X86: Export the kvm_zap_gfn_range() for the SNP use Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 34/37] KVM: SVM: Add support to handle the RMP nested page fault Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 35/37] KVM: SVM: Provide support for SNP_GUEST_REQUEST NAE event Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 36/37] KVM: SVM: Use a VMSA physical address variable for populating VMCB Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 37/37] KVM: SVM: Support SEV-SNP AP Creation NAE event Brijesh Singh
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