From: Xin Li <xin3.li@intel.com>
To: linux-kernel@vger.kernel.org, x86@kernel.org, kvm@vger.kernel.org
Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de,
dave.hansen@linux.intel.com, hpa@zytor.com, peterz@infradead.org,
andrew.cooper3@citrix.com, seanjc@google.com,
pbonzini@redhat.com, ravi.v.shankar@intel.com,
jiangshanlai@gmail.com, shan.kang@intel.com
Subject: [PATCH v6 18/33] x86/fred: add a NMI entry stub for FRED
Date: Mon, 27 Mar 2023 00:58:23 -0700 [thread overview]
Message-ID: <20230327075838.5403-19-xin3.li@intel.com> (raw)
In-Reply-To: <20230327075838.5403-1-xin3.li@intel.com>
From: "H. Peter Anvin (Intel)" <hpa@zytor.com>
On a FRED system, NMIs nest both with themselves and faults, transient
information is saved into the stack frame, and NMI unblocking only
happens when the stack frame indicates that so should happen.
Thus, the NMI entry stub for FRED is really quite small...
Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Tested-by: Shan Kang <shan.kang@intel.com>
Signed-off-by: Xin Li <xin3.li@intel.com>
---
arch/x86/include/asm/fred.h | 1 +
arch/x86/kernel/nmi.c | 19 +++++++++++++++++++
2 files changed, 20 insertions(+)
diff --git a/arch/x86/include/asm/fred.h b/arch/x86/include/asm/fred.h
index 633dd9e6a68e..f928a03082af 100644
--- a/arch/x86/include/asm/fred.h
+++ b/arch/x86/include/asm/fred.h
@@ -94,6 +94,7 @@ static __always_inline unsigned long fred_event_data(struct pt_regs *regs)
#define DEFINE_FRED_HANDLER(f) noinstr DECLARE_FRED_HANDLER(f)
typedef DECLARE_FRED_HANDLER((*fred_handler));
+DECLARE_FRED_HANDLER(fred_exc_nmi);
DECLARE_FRED_HANDLER(fred_exc_debug);
DECLARE_FRED_HANDLER(fred_exc_page_fault);
diff --git a/arch/x86/kernel/nmi.c b/arch/x86/kernel/nmi.c
index 776f4b1e395b..e7b2abe42583 100644
--- a/arch/x86/kernel/nmi.c
+++ b/arch/x86/kernel/nmi.c
@@ -34,6 +34,7 @@
#include <asm/cache.h>
#include <asm/nospec-branch.h>
#include <asm/sev.h>
+#include <asm/fred.h>
#define CREATE_TRACE_POINTS
#include <trace/events/nmi.h>
@@ -643,6 +644,24 @@ void nmi_backtrace_stall_check(const struct cpumask *btp)
#endif
+#ifdef CONFIG_X86_FRED
+DEFINE_FRED_HANDLER(fred_exc_nmi)
+{
+ /*
+ * With FRED, CR2 and DR6 are pushed atomically on faults,
+ * so we don't have to worry about saving and restoring them.
+ * Breakpoint faults nest, so assume it is OK to leave DR7
+ * enabled.
+ */
+ irqentry_state_t irq_state = irqentry_nmi_enter(regs);
+
+ inc_irq_stat(__nmi_count);
+ default_do_nmi(regs);
+
+ irqentry_nmi_exit(regs, irq_state);
+}
+#endif
+
void stop_nmi(void)
{
ignore_nmis++;
--
2.34.1
next prev parent reply other threads:[~2023-03-27 8:25 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-27 7:58 [PATCH v6 00/33] x86: enable FRED for x86-64 Xin Li
2023-03-27 7:58 ` [PATCH v6 01/33] x86/traps: let common_interrupt() handle IRQ_MOVE_CLEANUP_VECTOR Xin Li
2023-03-27 7:58 ` [PATCH v6 02/33] x86/fred: make unions for the cs and ss fields in struct pt_regs Xin Li
2023-03-27 7:58 ` [PATCH v6 03/33] x86/traps: add a system interrupt table for system interrupt dispatch Xin Li
2023-03-27 7:58 ` [PATCH v6 04/33] x86/traps: add install_system_interrupt_handler() Xin Li
2023-03-27 7:58 ` [PATCH v6 05/33] x86/traps: add external_interrupt() to dispatch external interrupts Xin Li
2023-03-27 7:58 ` [PATCH v6 06/33] x86/cpufeature: add the cpu feature bit for FRED Xin Li
2023-03-27 7:58 ` [PATCH v6 07/33] x86/opcode: add ERETU, ERETS instructions to x86-opcode-map Xin Li
2023-03-27 7:58 ` [PATCH v6 08/33] x86/objtool: teach objtool about ERETU and ERETS Xin Li
2023-03-27 7:58 ` [PATCH v6 09/33] x86/cpu: add X86_CR4_FRED macro Xin Li
2023-03-27 7:58 ` [PATCH v6 10/33] x86/fred: add Kconfig option for FRED (CONFIG_X86_FRED) Xin Li
2023-03-27 7:58 ` [PATCH v6 11/33] x86/fred: if CONFIG_X86_FRED is disabled, disable FRED support Xin Li
2023-03-27 7:58 ` [PATCH v6 12/33] x86/cpu: add MSR numbers for FRED configuration Xin Li
2023-03-27 7:58 ` [PATCH v6 13/33] x86/fred: header file for event types Xin Li
2023-03-27 7:58 ` [PATCH v6 14/33] x86/fred: header file with FRED definitions Xin Li
2023-03-27 7:58 ` [PATCH v6 15/33] x86/fred: reserve space for the FRED stack frame Xin Li
2023-03-27 7:58 ` [PATCH v6 16/33] x86/fred: add a page fault entry stub for FRED Xin Li
2023-03-27 7:58 ` [PATCH v6 17/33] x86/fred: add a debug " Xin Li
2023-03-27 7:58 ` Xin Li [this message]
2023-03-27 7:58 ` [PATCH v6 19/33] x86/fred: add a machine check " Xin Li
2023-03-27 7:58 ` [PATCH v6 20/33] x86/fred: FRED entry/exit and dispatch code Xin Li
2023-03-27 7:58 ` [PATCH v6 21/33] x86/fred: FRED initialization code Xin Li
2023-03-27 7:58 ` [PATCH v6 22/33] x86/fred: update MSR_IA32_FRED_RSP0 during task switch Xin Li
2023-03-27 7:58 ` [PATCH v6 23/33] x86/fred: let ret_from_fork() jmp to fred_exit_user when FRED is enabled Xin Li
2023-03-27 7:58 ` [PATCH v6 24/33] x86/fred: disallow the swapgs instruction " Xin Li
2023-03-27 7:58 ` [PATCH v6 25/33] x86/fred: no ESPFIX needed " Xin Li
2023-03-27 7:58 ` [PATCH v6 26/33] x86/fred: allow single-step trap and NMI when starting a new thread Xin Li
2023-03-27 7:58 ` [PATCH v6 27/33] x86/fred: fixup fault on ERETU by jumping to fred_entrypoint_user Xin Li
2023-03-31 8:03 ` Lai Jiangshan
2023-04-01 8:12 ` Li, Xin3
2023-03-27 7:58 ` [PATCH v6 28/33] x86/ia32: do not modify the DPL bits for a null selector Xin Li
2023-03-27 7:58 ` [PATCH v6 29/33] x86/fred: allow FRED systems to use interrupt vectors 0x10-0x1f Xin Li
2023-03-27 7:58 ` [PATCH v6 30/33] x86/fred: allow dynamic stack frame size Xin Li
2023-03-27 7:58 ` [PATCH v6 31/33] x86/fred: BUG() when ERETU with %rsp not equal to that when the ring 3 event was just delivered Xin Li
2023-03-27 7:58 ` [PATCH v6 32/33] x86/fred: disable FRED by default in its early stage Xin Li
2023-03-27 7:58 ` [PATCH v6 33/33] KVM: x86/vmx: refactor VMX_DO_EVENT_IRQOFF to generate FRED stack frames Xin Li
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