diff mbox

[V4,10/10] arm64: KVM: add guest SEA support

Message ID 1477071013-29563-11-git-send-email-tbaicar@codeaurora.org (mailing list archive)
State Not Applicable, archived
Headers show

Commit Message

Tyler Baicar Oct. 21, 2016, 5:30 p.m. UTC
Currently external aborts are unsupported by the guest abort
handling. Add handling for SEAs so that the host kernel reports
SEAs which occur in the guest kernel.

Signed-off-by: Tyler Baicar <tbaicar@codeaurora.org>
---
 arch/arm/include/asm/kvm_arm.h       |  1 +
 arch/arm/include/asm/system_misc.h   |  5 +++++
 arch/arm/kvm/mmu.c                   | 18 ++++++++++++++++--
 arch/arm64/include/asm/kvm_arm.h     |  1 +
 arch/arm64/include/asm/system_misc.h |  2 ++
 arch/arm64/mm/fault.c                | 13 +++++++++++++
 6 files changed, 38 insertions(+), 2 deletions(-)

Comments

Russell King (Oracle) Oct. 31, 2016, 10:02 a.m. UTC | #1
The subject line on this patch is misleading - it's not only ARM64
specific...

On Fri, Oct 21, 2016 at 11:30:13AM -0600, Tyler Baicar wrote:
> diff --git a/arch/arm/include/asm/system_misc.h b/arch/arm/include/asm/system_misc.h
> index a3d61ad..86e1faa 100644
> --- a/arch/arm/include/asm/system_misc.h
> +++ b/arch/arm/include/asm/system_misc.h
> @@ -24,4 +24,9 @@ extern unsigned int user_debug;
>  
>  #endif /* !__ASSEMBLY__ */
>  
> +inline int handle_guest_sea(unsigned long addr, unsigned int esr)

This needs to be static.

> +{
> +	return -1;
> +}
> +
>  #endif /* __ASM_ARM_SYSTEM_MISC_H */
Tyler Baicar Oct. 31, 2016, 10:36 p.m. UTC | #2
Hello Russell,

On 10/31/2016 4:02 AM, Russell King - ARM Linux wrote:
> The subject line on this patch is misleading - it's not only ARM64
> specific...
Thank you for the feedback!

I only put ARM64 in the subject line because this patch only really adds 
guest SEA support for the ARM64 KVM code. The ARM code had to be edited 
since both the ARM and ARM64 KVM code use arch/arm/kvm/mmu.c. I can 
change the subject line to "arm/arm64: KVM: add guest SEA support" if 
you think that is better.
> On Fri, Oct 21, 2016 at 11:30:13AM -0600, Tyler Baicar wrote:
>> diff --git a/arch/arm/include/asm/system_misc.h b/arch/arm/include/asm/system_misc.h
>> index a3d61ad..86e1faa 100644
>> --- a/arch/arm/include/asm/system_misc.h
>> +++ b/arch/arm/include/asm/system_misc.h
>> @@ -24,4 +24,9 @@ extern unsigned int user_debug;
>>   
>>   #endif /* !__ASSEMBLY__ */
>>   
>> +inline int handle_guest_sea(unsigned long addr, unsigned int esr)
> This needs to be static.
I'll make this static.

Thanks,
Tyler
>> +{
>> +	return -1;
>> +}
>> +
>>   #endif /* __ASM_ARM_SYSTEM_MISC_H */
Russell King (Oracle) Nov. 1, 2016, 9:36 a.m. UTC | #3
On Mon, Oct 31, 2016 at 04:36:33PM -0600, Baicar, Tyler wrote:
> Hello Russell,
> 
> On 10/31/2016 4:02 AM, Russell King - ARM Linux wrote:
> >The subject line on this patch is misleading - it's not only ARM64
> >specific...
> Thank you for the feedback!
> 
> I only put ARM64 in the subject line because this patch only really adds
> guest SEA support for the ARM64 KVM code. The ARM code had to be edited
> since both the ARM and ARM64 KVM code use arch/arm/kvm/mmu.c. I can change
> the subject line to "arm/arm64: KVM: add guest SEA support" if you think
> that is better.

Yes please, I almost skipped over it while catching up because it didn't
say "arm", it was only that I'd happened to read the cover message that
I'd spotted arch/arm in the diffstat, and then had to go digging for the
changes to review.
diff mbox

Patch

diff --git a/arch/arm/include/asm/kvm_arm.h b/arch/arm/include/asm/kvm_arm.h
index e22089f..33a77509 100644
--- a/arch/arm/include/asm/kvm_arm.h
+++ b/arch/arm/include/asm/kvm_arm.h
@@ -187,6 +187,7 @@ 
 #define FSC_FAULT	(0x04)
 #define FSC_ACCESS	(0x08)
 #define FSC_PERM	(0x0c)
+#define FSC_EXTABT	(0x10)
 
 /* Hyp Prefetch Fault Address Register (HPFAR/HDFAR) */
 #define HPFAR_MASK	(~0xf)
diff --git a/arch/arm/include/asm/system_misc.h b/arch/arm/include/asm/system_misc.h
index a3d61ad..86e1faa 100644
--- a/arch/arm/include/asm/system_misc.h
+++ b/arch/arm/include/asm/system_misc.h
@@ -24,4 +24,9 @@  extern unsigned int user_debug;
 
 #endif /* !__ASSEMBLY__ */
 
+inline int handle_guest_sea(unsigned long addr, unsigned int esr)
+{
+	return -1;
+}
+
 #endif /* __ASM_ARM_SYSTEM_MISC_H */
diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c
index e9a5c0e..1152966 100644
--- a/arch/arm/kvm/mmu.c
+++ b/arch/arm/kvm/mmu.c
@@ -29,6 +29,7 @@ 
 #include <asm/kvm_asm.h>
 #include <asm/kvm_emulate.h>
 #include <asm/virt.h>
+#include <asm/system_misc.h>
 
 #include "trace.h"
 
@@ -1441,8 +1442,21 @@  int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run)
 
 	/* Check the stage-2 fault is trans. fault or write fault */
 	fault_status = kvm_vcpu_trap_get_fault_type(vcpu);
-	if (fault_status != FSC_FAULT && fault_status != FSC_PERM &&
-	    fault_status != FSC_ACCESS) {
+
+	/* The host kernel will handle the synchronous external abort. There
+	 * is no need to pass the error into the guest.
+	 */
+	if (fault_status == FSC_EXTABT) {
+		if(handle_guest_sea((unsigned long)fault_ipa,
+				    kvm_vcpu_get_hsr(vcpu))) {
+			kvm_err("Failed to handle guest SEA, FSC: EC=%#x xFSC=%#lx ESR_EL2=%#lx\n",
+				kvm_vcpu_trap_get_class(vcpu),
+				(unsigned long)kvm_vcpu_trap_get_fault(vcpu),
+				(unsigned long)kvm_vcpu_get_hsr(vcpu));
+			return -EFAULT;
+		}
+	} else if (fault_status != FSC_FAULT && fault_status != FSC_PERM &&
+		   fault_status != FSC_ACCESS) {
 		kvm_err("Unsupported FSC: EC=%#x xFSC=%#lx ESR_EL2=%#lx\n",
 			kvm_vcpu_trap_get_class(vcpu),
 			(unsigned long)kvm_vcpu_trap_get_fault(vcpu),
diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h
index 4b5c977..be0efb6 100644
--- a/arch/arm64/include/asm/kvm_arm.h
+++ b/arch/arm64/include/asm/kvm_arm.h
@@ -201,6 +201,7 @@ 
 #define FSC_FAULT	ESR_ELx_FSC_FAULT
 #define FSC_ACCESS	ESR_ELx_FSC_ACCESS
 #define FSC_PERM	ESR_ELx_FSC_PERM
+#define FSC_EXTABT	ESR_ELx_FSC_EXTABT
 
 /* Hyp Prefetch Fault Address Register (HPFAR/HDFAR) */
 #define HPFAR_MASK	(~UL(0xf))
diff --git a/arch/arm64/include/asm/system_misc.h b/arch/arm64/include/asm/system_misc.h
index 9040e1d..3a142a5 100644
--- a/arch/arm64/include/asm/system_misc.h
+++ b/arch/arm64/include/asm/system_misc.h
@@ -77,4 +77,6 @@  extern void (*arm_pm_restart)(enum reboot_mode reboot_mode, const char *cmd);
 int register_synchronous_ext_abort_notifier(struct notifier_block *nb);
 void unregister_synchronous_ext_abort_notifier(struct notifier_block *nb);
 
+int handle_guest_sea(unsigned long addr, unsigned int esr);
+
 #endif	/* __ASM_SYSTEM_MISC_H */
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index fcc49f1..691399e 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -597,6 +597,19 @@  static const char *fault_name(unsigned int esr)
 }
 
 /*
+ * Handle Synchronous External Aborts that occur in a guest kernel.
+ */
+int handle_guest_sea(unsigned long addr, unsigned int esr)
+{
+	atomic_notifier_call_chain(&sea_handler_chain, 0, NULL);
+
+	pr_err("Synchronous External Abort: %s (0x%08x) at 0x%016lx\n",
+		fault_name(esr), esr, addr);
+
+	return 0;
+}
+
+/*
  * Dispatch a data abort to the relevant handler.
  */
 asmlinkage void __exception do_mem_abort(unsigned long addr, unsigned int esr,