From: Brijesh Singh <brijesh.singh@amd.com>
To: linux-kernel@vger.kernel.org, x86@kernel.org,
kvm@vger.kernel.org, linux-crypto@vger.kernel.org
Cc: ak@linux.intel.com, herbert@gondor.apana.org.au,
Brijesh Singh <brijesh.singh@amd.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Joerg Roedel <jroedel@suse.de>, "H. Peter Anvin" <hpa@zytor.com>,
Tony Luck <tony.luck@intel.com>,
Dave Hansen <dave.hansen@intel.com>,
"Peter Zijlstra (Intel)" <peterz@infradead.org>,
Paolo Bonzini <pbonzini@redhat.com>,
Tom Lendacky <thomas.lendacky@amd.com>,
David Rientjes <rientjes@google.com>,
Sean Christopherson <seanjc@google.com>
Subject: [RFC Part2 PATCH 06/30] x86/fault: dump the RMP entry on #PF
Date: Wed, 24 Mar 2021 12:04:12 -0500 [thread overview]
Message-ID: <20210324170436.31843-7-brijesh.singh@amd.com> (raw)
In-Reply-To: <20210324170436.31843-1-brijesh.singh@amd.com>
If hardware detects an RMP violation, it will raise a page-fault exception
with the RMP bit set. To help the debug, dump the RMP entry of the faulting
address.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: x86@kernel.org
Cc: kvm@vger.kernel.org
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
---
arch/x86/mm/fault.c | 75 +++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 75 insertions(+)
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index f39b551f89a6..7605e06a6dd9 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -31,6 +31,7 @@
#include <asm/pgtable_areas.h> /* VMALLOC_START, ... */
#include <asm/kvm_para.h> /* kvm_handle_async_pf */
#include <asm/vdso.h> /* fixup_vdso_exception() */
+#include <asm/sev-snp.h> /* lookup_rmpentry ... */
#define CREATE_TRACE_POINTS
#include <asm/trace/exceptions.h>
@@ -147,6 +148,76 @@ is_prefetch(struct pt_regs *regs, unsigned long error_code, unsigned long addr)
DEFINE_SPINLOCK(pgd_lock);
LIST_HEAD(pgd_list);
+static void dump_rmpentry(struct page *page, rmpentry_t *e)
+{
+ unsigned long paddr = page_to_pfn(page) << PAGE_SHIFT;
+
+ pr_alert("RMPEntry paddr 0x%lx [assigned=%d immutable=%d pagesize=%d gpa=0x%lx asid=%d "
+ "vmsa=%d validated=%d]\n", paddr, 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", paddr, e->high, e->low);
+}
+
+static void show_rmpentry(unsigned long address)
+{
+ struct page *page = virt_to_page(address);
+ rmpentry_t *entry, *large_entry;
+ int level, rmp_level;
+ pgd_t *pgd;
+ pte_t *pte;
+
+ /* Get the RMP entry for the fault address */
+ entry = lookup_page_in_rmptable(page, &rmp_level);
+ if (!entry) {
+ pr_alert("SEV-SNP: failed to read RMP entry for address 0x%lx\n", address);
+ return;
+ }
+
+ dump_rmpentry(page, entry);
+
+ /*
+ * If fault occurred during the large page walk, dump the RMP entry at base of 2MB page.
+ */
+ pgd = __va(read_cr3_pa());
+ pgd += pgd_index(address);
+ pte = lookup_address_in_pgd(pgd, address, &level);
+ if ((level > PG_LEVEL_4K) && (!IS_ALIGNED(address, PMD_SIZE))) {
+ address = address & PMD_MASK;
+ large_entry = lookup_page_in_rmptable(virt_to_page(address), &rmp_level);
+ if (!large_entry) {
+ pr_alert("SEV-SNP: failed to read large RMP entry 0x%lx\n",
+ address & PMD_MASK);
+ return;
+ }
+
+ dump_rmpentry(virt_to_page(address), large_entry);
+ }
+
+ /*
+ * 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(entry)) {
+ unsigned long start, end;
+
+ start = address & PMD_MASK;
+ end = start + PMD_SIZE;
+
+ for (; start < end; start += PAGE_SIZE) {
+ entry = lookup_page_in_rmptable(virt_to_page(start), &rmp_level);
+ if (!entry)
+ return;
+
+ /* If any of the bits in RMP entry is set then dump it */
+ if (entry->high || entry->low)
+ pr_alert("RMPEntry paddr %lx: %016llx %016llx\n",
+ page_to_pfn(page) << PAGE_SHIFT, entry->high, entry->low);
+ }
+ }
+}
+
#ifdef CONFIG_X86_32
static inline pmd_t *vmalloc_sync_one(pgd_t *pgd, unsigned long address)
{
@@ -580,6 +651,10 @@ show_fault_oops(struct pt_regs *regs, unsigned long error_code, unsigned long ad
}
dump_pagetable(address);
+
+ if (error_code & X86_PF_RMP)
+ show_rmpentry(address);
+
}
static noinline void
--
2.17.1
next prev parent reply other threads:[~2021-03-24 17:05 UTC|newest]
Thread overview: 69+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-24 17:04 [RFC Part2 PATCH 00/30] Add AMD Secure Nested Paging (SEV-SNP) Hypervisor Support Brijesh Singh
2021-03-24 17:04 ` [RFC Part2 PATCH 01/30] x86: Add the host SEV-SNP initialization support Brijesh Singh
2021-03-25 14:58 ` Dave Hansen
2021-03-25 15:31 ` Brijesh Singh
2021-03-25 15:51 ` Dave Hansen
2021-03-25 17:41 ` Brijesh Singh
2021-04-14 7:27 ` Borislav Petkov
2021-04-14 22:48 ` Brijesh Singh
2021-03-24 17:04 ` [RFC Part2 PATCH 02/30] x86/sev-snp: add RMP entry lookup helpers Brijesh Singh
2021-04-15 16:57 ` Borislav Petkov
2021-04-15 18:08 ` Brijesh Singh
2021-04-15 19:50 ` Borislav Petkov
2021-04-15 22:18 ` Brijesh Singh
2021-04-15 17:03 ` Borislav Petkov
2021-04-15 18:09 ` Brijesh Singh
2021-03-24 17:04 ` [RFC Part2 PATCH 03/30] x86: add helper functions for RMPUPDATE and PSMASH instruction Brijesh Singh
2021-04-15 18:00 ` Borislav Petkov
2021-04-15 18:15 ` Brijesh Singh
2021-03-24 17:04 ` [RFC Part2 PATCH 04/30] x86/mm: split the physmap when adding the page in RMP table Brijesh Singh
2021-03-25 15:17 ` Dave Hansen
2021-04-19 12:32 ` Borislav Petkov
2021-04-19 15:25 ` Brijesh Singh
2021-04-19 16:52 ` Borislav Petkov
[not found] ` <30bff969-e8cf-a991-7660-054ea136855a@amd.com>
2021-04-19 17:58 ` Dave Hansen
2021-04-19 18:10 ` Andy Lutomirski
2021-04-19 18:33 ` Dave Hansen
2021-04-19 18:37 ` Andy Lutomirski
2021-04-20 9:51 ` Borislav Petkov
2021-04-19 21:25 ` Brijesh Singh
2021-04-20 9:47 ` Borislav Petkov
2021-03-24 17:04 ` [RFC Part2 PATCH 05/30] x86: define RMP violation #PF error code Brijesh Singh
2021-03-24 18:03 ` Dave Hansen
2021-03-25 14:32 ` Brijesh Singh
2021-03-25 14:34 ` Dave Hansen
2021-04-20 10:32 ` Borislav Petkov
2021-04-20 21:37 ` Brijesh Singh
2021-03-24 17:04 ` Brijesh Singh [this message]
2021-03-24 17:47 ` [RFC Part2 PATCH 06/30] x86/fault: dump the RMP entry on #PF Andy Lutomirski
2021-03-24 20:35 ` Brijesh Singh
2021-03-24 17:04 ` [RFC Part2 PATCH 07/30] mm: add support to split the large THP based on RMP violation Brijesh Singh
2021-03-25 14:30 ` Dave Hansen
2021-03-25 14:48 ` Dave Hansen
2021-03-25 15:24 ` Brijesh Singh
2021-03-25 15:59 ` Dave Hansen
2021-04-21 12:59 ` Vlastimil Babka
2021-04-21 13:43 ` Brijesh Singh
2021-03-24 17:04 ` [RFC Part2 PATCH 08/30] crypto:ccp: define the SEV-SNP commands Brijesh Singh
2021-03-24 17:04 ` [RFC Part2 PATCH 09/30] crypto: ccp: Add support to initialize the AMD-SP for SEV-SNP Brijesh Singh
2021-03-24 17:04 ` [RFC Part2 PATCH 10/30] crypto: ccp: shutdown SNP firmware on kexec Brijesh Singh
2021-03-24 17:04 ` [RFC Part2 PATCH 11/30] crypto:ccp: provide APIs to issue SEV-SNP commands Brijesh Singh
2021-03-24 17:04 ` [RFC Part2 PATCH 12/30] crypto ccp: handle the legacy SEV command when SNP is enabled Brijesh Singh
2021-03-24 17:04 ` [RFC Part2 PATCH 13/30] KVM: SVM: add initial SEV-SNP support Brijesh Singh
2021-03-24 17:04 ` [RFC Part2 PATCH 14/30] KVM: SVM: make AVIC backing, VMSA and VMCB memory allocation SNP safe Brijesh Singh
2021-03-24 17:04 ` [RFC Part2 PATCH 15/30] KVM: SVM: define new SEV_FEATURES field in the VMCB Save State Area Brijesh Singh
2021-03-24 17:04 ` [RFC Part2 PATCH 16/30] KVM: SVM: add KVM_SNP_INIT command Brijesh Singh
2021-03-24 17:04 ` [RFC Part2 PATCH 17/30] KVM: SVM: add KVM_SEV_SNP_LAUNCH_START command Brijesh Singh
2021-03-24 17:04 ` [RFC Part2 PATCH 18/30] KVM: SVM: add KVM_SEV_SNP_LAUNCH_UPDATE command Brijesh Singh
2021-03-24 17:04 ` [RFC Part2 PATCH 19/30] KVM: SVM: Reclaim the guest pages when SEV-SNP VM terminates Brijesh Singh
2021-03-24 17:04 ` [RFC Part2 PATCH 20/30] KVM: SVM: add KVM_SEV_SNP_LAUNCH_FINISH command Brijesh Singh
2021-03-24 17:04 ` [RFC Part2 PATCH 21/30] KVM: X86: Add kvm_x86_ops to get the max page level for the TDP Brijesh Singh
2021-03-24 17:04 ` [RFC Part2 PATCH 22/30] x86/mmu: Introduce kvm_mmu_map_tdp_page() for use by SEV Brijesh Singh
2021-03-24 17:04 ` [RFC Part2 PATCH 23/30] KVM: X86: Introduce kvm_mmu_get_tdp_walk() for SEV-SNP use Brijesh Singh
2021-03-24 17:04 ` [RFC Part2 PATCH 24/30] KVM: X86: define new RMP check related #NPF error bits Brijesh Singh
2021-03-24 17:04 ` [RFC Part2 PATCH 25/30] KVM: X86: update page-fault trace to log the 64-bit error code Brijesh Singh
2021-03-24 17:04 ` [RFC Part2 PATCH 26/30] KVM: SVM: add support to handle GHCB GPA register VMGEXIT Brijesh Singh
2021-03-24 17:04 ` [RFC Part2 PATCH 27/30] KVM: SVM: add support to handle MSR based Page State Change VMGEXIT Brijesh Singh
2021-03-24 17:04 ` [RFC Part2 PATCH 28/30] KVM: SVM: add support to handle " Brijesh Singh
2021-03-24 17:04 ` [RFC Part2 PATCH 29/30] KVM: X86: export the kvm_zap_gfn_range() for the SNP use Brijesh Singh
2021-03-24 17:04 ` [RFC Part2 PATCH 30/30] KVM: X86: Add support to handle the RMP nested page fault Brijesh Singh
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