* [PATCH] arm64: KVM: VHE: Context switch MDSCR_EL1
@ 2016-07-19 8:57 Marc Zyngier
2016-07-19 12:25 ` Paolo Bonzini
0 siblings, 1 reply; 3+ messages in thread
From: Marc Zyngier @ 2016-07-19 8:57 UTC (permalink / raw)
To: linux-arm-kernel
The kprobe enablement work has uncovered that changes made by
a guest to MDSCR_EL1 were propagated to the host when VHE was
enabled, leading to unexpected exception being delivered.
Moving this register to the list of registers that are always
context-switched fixes the issue.
Reported-by: Tirumalesh Chalamarla <Tirumalesh.Chalamarla@cavium.com>
Tested-by: Tirumalesh Chalamarla <Tirumalesh.Chalamarla@cavium.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
arch/arm64/kvm/hyp/sysreg-sr.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/arch/arm64/kvm/hyp/sysreg-sr.c b/arch/arm64/kvm/hyp/sysreg-sr.c
index 0f7c40e..a327e35 100644
--- a/arch/arm64/kvm/hyp/sysreg-sr.c
+++ b/arch/arm64/kvm/hyp/sysreg-sr.c
@@ -27,8 +27,8 @@ static void __hyp_text __sysreg_do_nothing(struct kvm_cpu_context *ctxt) { }
/*
* Non-VHE: Both host and guest must save everything.
*
- * VHE: Host must save tpidr*_el[01], actlr_el1, sp0, pc, pstate, and
- * guest must save everything.
+ * VHE: Host must save tpidr*_el[01], actlr_el1, mdscr_el1, sp0, pc,
+ * pstate, and guest must save everything.
*/
static void __hyp_text __sysreg_save_common_state(struct kvm_cpu_context *ctxt)
@@ -37,6 +37,7 @@ static void __hyp_text __sysreg_save_common_state(struct kvm_cpu_context *ctxt)
ctxt->sys_regs[TPIDR_EL0] = read_sysreg(tpidr_el0);
ctxt->sys_regs[TPIDRRO_EL0] = read_sysreg(tpidrro_el0);
ctxt->sys_regs[TPIDR_EL1] = read_sysreg(tpidr_el1);
+ ctxt->sys_regs[MDSCR_EL1] = read_sysreg(mdscr_el1);
ctxt->gp_regs.regs.sp = read_sysreg(sp_el0);
ctxt->gp_regs.regs.pc = read_sysreg_el2(elr);
ctxt->gp_regs.regs.pstate = read_sysreg_el2(spsr);
@@ -61,7 +62,6 @@ static void __hyp_text __sysreg_save_state(struct kvm_cpu_context *ctxt)
ctxt->sys_regs[AMAIR_EL1] = read_sysreg_el1(amair);
ctxt->sys_regs[CNTKCTL_EL1] = read_sysreg_el1(cntkctl);
ctxt->sys_regs[PAR_EL1] = read_sysreg(par_el1);
- ctxt->sys_regs[MDSCR_EL1] = read_sysreg(mdscr_el1);
ctxt->gp_regs.sp_el1 = read_sysreg(sp_el1);
ctxt->gp_regs.elr_el1 = read_sysreg_el1(elr);
@@ -90,6 +90,7 @@ static void __hyp_text __sysreg_restore_common_state(struct kvm_cpu_context *ctx
write_sysreg(ctxt->sys_regs[TPIDR_EL0], tpidr_el0);
write_sysreg(ctxt->sys_regs[TPIDRRO_EL0], tpidrro_el0);
write_sysreg(ctxt->sys_regs[TPIDR_EL1], tpidr_el1);
+ write_sysreg(ctxt->sys_regs[MDSCR_EL1], mdscr_el1);
write_sysreg(ctxt->gp_regs.regs.sp, sp_el0);
write_sysreg_el2(ctxt->gp_regs.regs.pc, elr);
write_sysreg_el2(ctxt->gp_regs.regs.pstate, spsr);
@@ -114,7 +115,6 @@ static void __hyp_text __sysreg_restore_state(struct kvm_cpu_context *ctxt)
write_sysreg_el1(ctxt->sys_regs[AMAIR_EL1], amair);
write_sysreg_el1(ctxt->sys_regs[CNTKCTL_EL1], cntkctl);
write_sysreg(ctxt->sys_regs[PAR_EL1], par_el1);
- write_sysreg(ctxt->sys_regs[MDSCR_EL1], mdscr_el1);
write_sysreg(ctxt->gp_regs.sp_el1, sp_el1);
write_sysreg_el1(ctxt->gp_regs.elr_el1, elr);
--
2.1.4
^ permalink raw reply related [flat|nested] 3+ messages in thread
* [PATCH] arm64: KVM: VHE: Context switch MDSCR_EL1
2016-07-19 8:57 [PATCH] arm64: KVM: VHE: Context switch MDSCR_EL1 Marc Zyngier
@ 2016-07-19 12:25 ` Paolo Bonzini
2016-07-19 12:44 ` Marc Zyngier
0 siblings, 1 reply; 3+ messages in thread
From: Paolo Bonzini @ 2016-07-19 12:25 UTC (permalink / raw)
To: linux-arm-kernel
On 19/07/2016 10:57, Marc Zyngier wrote:
> The kprobe enablement work has uncovered that changes made by
> a guest to MDSCR_EL1 were propagated to the host when VHE was
> enabled, leading to unexpected exception being delivered.
>
> Moving this register to the list of registers that are always
> context-switched fixes the issue.
>
> Reported-by: Tirumalesh Chalamarla <Tirumalesh.Chalamarla@cavium.com>
> Tested-by: Tirumalesh Chalamarla <Tirumalesh.Chalamarla@cavium.com>
> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
> ---
> arch/arm64/kvm/hyp/sysreg-sr.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/arch/arm64/kvm/hyp/sysreg-sr.c b/arch/arm64/kvm/hyp/sysreg-sr.c
> index 0f7c40e..a327e35 100644
> --- a/arch/arm64/kvm/hyp/sysreg-sr.c
> +++ b/arch/arm64/kvm/hyp/sysreg-sr.c
> @@ -27,8 +27,8 @@ static void __hyp_text __sysreg_do_nothing(struct kvm_cpu_context *ctxt) { }
> /*
> * Non-VHE: Both host and guest must save everything.
> *
> - * VHE: Host must save tpidr*_el[01], actlr_el1, sp0, pc, pstate, and
> - * guest must save everything.
> + * VHE: Host must save tpidr*_el[01], actlr_el1, mdscr_el1, sp0, pc,
> + * pstate, and guest must save everything.
> */
>
> static void __hyp_text __sysreg_save_common_state(struct kvm_cpu_context *ctxt)
> @@ -37,6 +37,7 @@ static void __hyp_text __sysreg_save_common_state(struct kvm_cpu_context *ctxt)
> ctxt->sys_regs[TPIDR_EL0] = read_sysreg(tpidr_el0);
> ctxt->sys_regs[TPIDRRO_EL0] = read_sysreg(tpidrro_el0);
> ctxt->sys_regs[TPIDR_EL1] = read_sysreg(tpidr_el1);
> + ctxt->sys_regs[MDSCR_EL1] = read_sysreg(mdscr_el1);
> ctxt->gp_regs.regs.sp = read_sysreg(sp_el0);
> ctxt->gp_regs.regs.pc = read_sysreg_el2(elr);
> ctxt->gp_regs.regs.pstate = read_sysreg_el2(spsr);
> @@ -61,7 +62,6 @@ static void __hyp_text __sysreg_save_state(struct kvm_cpu_context *ctxt)
> ctxt->sys_regs[AMAIR_EL1] = read_sysreg_el1(amair);
> ctxt->sys_regs[CNTKCTL_EL1] = read_sysreg_el1(cntkctl);
> ctxt->sys_regs[PAR_EL1] = read_sysreg(par_el1);
> - ctxt->sys_regs[MDSCR_EL1] = read_sysreg(mdscr_el1);
>
> ctxt->gp_regs.sp_el1 = read_sysreg(sp_el1);
> ctxt->gp_regs.elr_el1 = read_sysreg_el1(elr);
> @@ -90,6 +90,7 @@ static void __hyp_text __sysreg_restore_common_state(struct kvm_cpu_context *ctx
> write_sysreg(ctxt->sys_regs[TPIDR_EL0], tpidr_el0);
> write_sysreg(ctxt->sys_regs[TPIDRRO_EL0], tpidrro_el0);
> write_sysreg(ctxt->sys_regs[TPIDR_EL1], tpidr_el1);
> + write_sysreg(ctxt->sys_regs[MDSCR_EL1], mdscr_el1);
> write_sysreg(ctxt->gp_regs.regs.sp, sp_el0);
> write_sysreg_el2(ctxt->gp_regs.regs.pc, elr);
> write_sysreg_el2(ctxt->gp_regs.regs.pstate, spsr);
> @@ -114,7 +115,6 @@ static void __hyp_text __sysreg_restore_state(struct kvm_cpu_context *ctxt)
> write_sysreg_el1(ctxt->sys_regs[AMAIR_EL1], amair);
> write_sysreg_el1(ctxt->sys_regs[CNTKCTL_EL1], cntkctl);
> write_sysreg(ctxt->sys_regs[PAR_EL1], par_el1);
> - write_sysreg(ctxt->sys_regs[MDSCR_EL1], mdscr_el1);
>
> write_sysreg(ctxt->gp_regs.sp_el1, sp_el1);
> write_sysreg_el1(ctxt->gp_regs.elr_el1, elr);
>
Can you add Fixes and Cc: stable headers? Thanks,
Paolo
^ permalink raw reply [flat|nested] 3+ messages in thread
* [PATCH] arm64: KVM: VHE: Context switch MDSCR_EL1
2016-07-19 12:25 ` Paolo Bonzini
@ 2016-07-19 12:44 ` Marc Zyngier
0 siblings, 0 replies; 3+ messages in thread
From: Marc Zyngier @ 2016-07-19 12:44 UTC (permalink / raw)
To: linux-arm-kernel
On 19/07/16 13:25, Paolo Bonzini wrote:
>
>
> On 19/07/2016 10:57, Marc Zyngier wrote:
>> The kprobe enablement work has uncovered that changes made by
>> a guest to MDSCR_EL1 were propagated to the host when VHE was
>> enabled, leading to unexpected exception being delivered.
>>
>> Moving this register to the list of registers that are always
>> context-switched fixes the issue.
>>
>> Reported-by: Tirumalesh Chalamarla <Tirumalesh.Chalamarla@cavium.com>
>> Tested-by: Tirumalesh Chalamarla <Tirumalesh.Chalamarla@cavium.com>
>> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
>> ---
>> arch/arm64/kvm/hyp/sysreg-sr.c | 8 ++++----
>> 1 file changed, 4 insertions(+), 4 deletions(-)
[...]
> Can you add Fixes and Cc: stable headers? Thanks,
Ah, I missed that. Thanks for the heads up, v2 coming shortly.
M.
--
Jazz is not dead. It just smells funny...
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2016-07-19 12:44 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2016-07-19 8:57 [PATCH] arm64: KVM: VHE: Context switch MDSCR_EL1 Marc Zyngier
2016-07-19 12:25 ` Paolo Bonzini
2016-07-19 12:44 ` Marc Zyngier
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).