[PATCH v6 09/13] KVM: arm64: Save/Restore guest DISR_EL1
James Morse
james.morse at arm.com
Mon Jan 15 11:39:02 PST 2018
If we deliver a virtual SError to the guest, the guest may defer it
with an ESB instruction. The guest reads the deferred value via DISR_EL1,
but the guests view of DISR_EL1 is re-mapped to VDISR_EL2 when HCR_EL2.AMO
is set.
Add the KVM code to save/restore VDISR_EL2, and make it accessible to
userspace as DISR_EL1.
Signed-off-by: James Morse <james.morse at arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier at arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall at linaro.org>
---
v5 of this patch missed some Reviewed-bys, which came from here:
https://patchwork.kernel.org/patch/10017465/
arch/arm64/include/asm/kvm_host.h | 1 +
arch/arm64/include/asm/sysreg.h | 1 +
arch/arm64/kvm/hyp/sysreg-sr.c | 6 ++++++
arch/arm64/kvm/sys_regs.c | 1 +
4 files changed, 9 insertions(+)
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 3014b39b8fe2..84fcb2a896a1 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -121,6 +121,7 @@ enum vcpu_sysreg {
PAR_EL1, /* Physical Address Register */
MDSCR_EL1, /* Monitor Debug System Control Register */
MDCCINT_EL1, /* Monitor Debug Comms Channel Interrupt Enable Reg */
+ DISR_EL1, /* Deferred Interrupt Status Register */
/* Performance Monitors Registers */
PMCR_EL0, /* Control Register */
diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h
index aec10f75a43c..e213bd92e998 100644
--- a/arch/arm64/include/asm/sysreg.h
+++ b/arch/arm64/include/asm/sysreg.h
@@ -358,6 +358,7 @@
#define SYS_VSESR_EL2 sys_reg(3, 4, 5, 2, 3)
#define SYS_FPEXC32_EL2 sys_reg(3, 4, 5, 3, 0)
+#define SYS_VDISR_EL2 sys_reg(3, 4, 12, 1, 1)
#define __SYS__AP0Rx_EL2(x) sys_reg(3, 4, 12, 8, x)
#define SYS_ICH_AP0R0_EL2 __SYS__AP0Rx_EL2(0)
#define SYS_ICH_AP0R1_EL2 __SYS__AP0Rx_EL2(1)
diff --git a/arch/arm64/kvm/hyp/sysreg-sr.c b/arch/arm64/kvm/hyp/sysreg-sr.c
index c54cc2afb92b..2c17afd2be96 100644
--- a/arch/arm64/kvm/hyp/sysreg-sr.c
+++ b/arch/arm64/kvm/hyp/sysreg-sr.c
@@ -66,6 +66,9 @@ static void __hyp_text __sysreg_save_state(struct kvm_cpu_context *ctxt)
ctxt->gp_regs.spsr[KVM_SPSR_EL1]= read_sysreg_el1(spsr);
ctxt->gp_regs.regs.pc = read_sysreg_el2(elr);
ctxt->gp_regs.regs.pstate = read_sysreg_el2(spsr);
+
+ if (cpus_have_const_cap(ARM64_HAS_RAS_EXTN))
+ ctxt->sys_regs[DISR_EL1] = read_sysreg_s(SYS_VDISR_EL2);
}
static hyp_alternate_select(__sysreg_call_save_host_state,
@@ -119,6 +122,9 @@ static void __hyp_text __sysreg_restore_state(struct kvm_cpu_context *ctxt)
write_sysreg_el1(ctxt->gp_regs.spsr[KVM_SPSR_EL1],spsr);
write_sysreg_el2(ctxt->gp_regs.regs.pc, elr);
write_sysreg_el2(ctxt->gp_regs.regs.pstate, spsr);
+
+ if (cpus_have_const_cap(ARM64_HAS_RAS_EXTN))
+ write_sysreg_s(ctxt->sys_regs[DISR_EL1], SYS_VDISR_EL2);
}
static hyp_alternate_select(__sysreg_call_restore_host_state,
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 1830ebc227d1..9edf4ac8a320 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -1169,6 +1169,7 @@ static const struct sys_reg_desc sys_reg_descs[] = {
{ SYS_DESC(SYS_AMAIR_EL1), access_vm_reg, reset_amair_el1, AMAIR_EL1 },
{ SYS_DESC(SYS_VBAR_EL1), NULL, reset_val, VBAR_EL1, 0 },
+ { SYS_DESC(SYS_DISR_EL1), NULL, reset_val, DISR_EL1, 0 },
{ SYS_DESC(SYS_ICC_IAR0_EL1), write_to_read_only },
{ SYS_DESC(SYS_ICC_EOIR0_EL1), read_from_write_only },
--
2.15.1
More information about the linux-arm-kernel
mailing list