From: "Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
We don't use PACATOC for PR. Avoid updating HOST_R2 with PR
KVM mode when both HV and PR are enabled in the kernel. Without this we
get the below crash
(qemu)
Unable to handle kernel paging request for data at address 0xffffffffffff8310
Faulting instruction address: 0xc00000000001d5a4
cpu 0x2: Vector: 300 (Data Access) at [c0000001dc53aef0]
pc: c00000000001d5a4: .vtime_delta.isra.1+0x34/0x1d0
lr: c00000000001d760: .vtime_account_system+0x20/0x60
sp: c0000001dc53b170
msr: 8000000000009032
dar: ffffffffffff8310
dsisr: 40000000
current = 0xc0000001d76c62d0
paca = 0xc00000000fef1100 softe: 0 irq_happened: 0x01
pid = 4472, comm = qemu-system-ppc
enter ? for help
[c0000001dc53b200] c00000000001d760 .vtime_account_system+0x20/0x60
[c0000001dc53b290] c00000000008d050 .kvmppc_handle_exit_pr+0x60/0xa50
[c0000001dc53b340] c00000000008f51c kvm_start_lightweight+0xb4/0xc4
[c0000001dc53b510] c00000000008cdf0 .kvmppc_vcpu_run_pr+0x150/0x2e0
[c0000001dc53b9e0] c00000000008341c .kvmppc_vcpu_run+0x2c/0x40
[c0000001dc53ba50] c000000000080af4 .kvm_arch_vcpu_ioctl_run+0x54/0x1b0
[c0000001dc53bae0] c00000000007b4c8 .kvm_vcpu_ioctl+0x478/0x730
[c0000001dc53bca0] c0000000002140cc .do_vfs_ioctl+0x4ac/0x770
[c0000001dc53bd80] c0000000002143e8 .SyS_ioctl+0x58/0xb0
[c0000001dc53be30] c000000000009e58 syscall_exit+0x0/0x98
--- Exception: c00 (System Call) at 00001fffff960160
SP (1ffffecbe3c0) is in userspace
These changes were originally part of
http://mid.gmane.org/20130806042205.GR19254@xxxxxxxxxxxxxxxxxxx
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
---
arch/powerpc/include/asm/kvm_book3s_asm.h | 1 +
arch/powerpc/kernel/asm-offsets.c | 1 +
arch/powerpc/kvm/book3s_hv_rmhandlers.S | 7 +++----
3 files changed, 5 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/include/asm/kvm_book3s_asm.h b/arch/powerpc/include/asm/kvm_book3s_asm.h
index 0bd9348..69fe837 100644
--- a/arch/powerpc/include/asm/kvm_book3s_asm.h
+++ b/arch/powerpc/include/asm/kvm_book3s_asm.h
@@ -79,6 +79,7 @@ struct kvmppc_host_state {
ulong vmhandler;
ulong scratch0;
ulong scratch1;
+ ulong scratch2;
u8 in_guest;
u8 restore_hid5;
u8 napping;
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index 8e6ede6..841a4c8 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -583,6 +583,7 @@ int main(void)
HSTATE_FIELD(HSTATE_VMHANDLER, vmhandler);
HSTATE_FIELD(HSTATE_SCRATCH0, scratch0);
HSTATE_FIELD(HSTATE_SCRATCH1, scratch1);
+ HSTATE_FIELD(HSTATE_SCRATCH2, scratch2);
HSTATE_FIELD(HSTATE_IN_GUEST, in_guest);
HSTATE_FIELD(HSTATE_RESTORE_HID5, restore_hid5);
HSTATE_FIELD(HSTATE_NAPPING, napping);
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index 339aa5e..16f7654 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -750,15 +750,14 @@ kvmppc_interrupt_hv:
* guest CR, R12 saved in shadow VCPU SCRATCH1/0
* guest R13 saved in SPRN_SCRATCH0
*/
- /* abuse host_r2 as third scratch area; we get r2 from PACATOC(r13) */
- std r9, HSTATE_HOST_R2(r13)
+ std r9, HSTATE_SCRATCH2(r13)
lbz r9, HSTATE_IN_GUEST(r13)
cmpwi r9, KVM_GUEST_MODE_HOST_HV
beq kvmppc_bad_host_intr
#ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
cmpwi r9, KVM_GUEST_MODE_GUEST
- ld r9, HSTATE_HOST_R2(r13)
+ ld r9, HSTATE_SCRATCH2(r13)
beq kvmppc_interrupt_pr
#endif
/* We're now back in the host but in guest MMU context */
@@ -778,7 +777,7 @@ kvmppc_interrupt_hv:
std r6, VCPU_GPR(R6)(r9)
std r7, VCPU_GPR(R7)(r9)
std r8, VCPU_GPR(R8)(r9)
- ld r0, HSTATE_HOST_R2(r13)
+ ld r0, HSTATE_SCRATCH2(r13)
std r0, VCPU_GPR(R9)(r9)
std r10, VCPU_GPR(R10)(r9)
std r11, VCPU_GPR(R11)(r9)
--
1.8.3.2
--
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