On 04/25/2014 01:29 PM, James Hogan wrote:
Hi David,
On Friday 25 April 2014 09:44:17 David Daney wrote:
On 04/25/2014 08:19 AM, James Hogan wrote:
Contrary to the comment, the guest CP0_EPC register cannot be set via
kvm_regs, since it is distinct from the guest PC. Add the EPC register
to the KVM_{GET,SET}_ONE_REG ioctl interface.
Signed-off-by: James Hogan <james.hogan@xxxxxxxxxx>
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Gleb Natapov <gleb@xxxxxxxxxx>
Cc: kvm@xxxxxxxxxxxxxxx
Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
Cc: linux-mips@xxxxxxxxxxxxxx
Cc: David Daney <david.daney@xxxxxxxxxx>
Cc: Sanjay Lal <sanjayl@xxxxxxxxxxx>
NACK...
---
arch/mips/kvm/kvm_mips.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/arch/mips/kvm/kvm_mips.c b/arch/mips/kvm/kvm_mips.c
index 46cea0bad518..db41876cbac5 100644
--- a/arch/mips/kvm/kvm_mips.c
+++ b/arch/mips/kvm/kvm_mips.c
@@ -512,6 +512,7 @@ kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu,
#define KVM_REG_MIPS_CP0_COMPARE MIPS_CP0_32(11, 0)
#define KVM_REG_MIPS_CP0_STATUS MIPS_CP0_32(12, 0)
#define KVM_REG_MIPS_CP0_CAUSE MIPS_CP0_32(13, 0)
+#define KVM_REG_MIPS_CP0_EPC MIPS_CP0_64(14, 0)
This is already called KVM_REG_MIPS_PC, you cannot change that.
KVM_REG_MIPS_PC gets you vcpu->arch.pc, i.e. the next address of guest
execution.
KVM_REG_MIPS_CP0_EPC gets you the guest's CP0 EPC register which is the PC of
the last guest exception.
They are quite distinct state, even though vcpu->arch.pc is read from the
*root context*'s CP0 EPC register after an exception or interrupt.
Sorry, my mistake. I was confusing Root/Host and Guest state.
I remove my objection.
David Daney
Cheers
James
#define KVM_REG_MIPS_CP0_EBASE MIPS_CP0_32(15, 1)
#define KVM_REG_MIPS_CP0_CONFIG MIPS_CP0_32(16, 0)
#define KVM_REG_MIPS_CP0_CONFIG1 MIPS_CP0_32(16, 1)
@@ -567,7 +568,7 @@ static u64 kvm_mips_get_one_regs[] = {
KVM_REG_MIPS_CP0_ENTRYHI,
KVM_REG_MIPS_CP0_STATUS,
KVM_REG_MIPS_CP0_CAUSE,
- /* EPC set via kvm_regs, et al. */
+ KVM_REG_MIPS_CP0_EPC,
KVM_REG_MIPS_CP0_CONFIG,
KVM_REG_MIPS_CP0_CONFIG1,
KVM_REG_MIPS_CP0_CONFIG2,
@@ -620,6 +621,9 @@ static int kvm_mips_get_reg(struct kvm_vcpu *vcpu,
case KVM_REG_MIPS_CP0_CAUSE:
v = (long)kvm_read_c0_guest_cause(cop0);
break;
+ case KVM_REG_MIPS_CP0_EPC:
+ v = (long)kvm_read_c0_guest_epc(cop0);
+ break;
case KVM_REG_MIPS_CP0_ERROREPC:
v = (long)kvm_read_c0_guest_errorepc(cop0);
break;
@@ -716,6 +720,9 @@ static int kvm_mips_set_reg(struct kvm_vcpu *vcpu,
case KVM_REG_MIPS_CP0_CAUSE:
kvm_write_c0_guest_cause(cop0, v);
break;
+ case KVM_REG_MIPS_CP0_EPC:
+ kvm_write_c0_guest_epc(cop0, v);
+ break;
case KVM_REG_MIPS_CP0_ERROREPC:
kvm_write_c0_guest_errorepc(cop0, v);
break;
