[v3,16/16] powerpc/kvm: Use the PACA virt/real mode info instead of mfmsr

Message ID 20180111043413.22655-16-benh@kernel.crashing.org
State Superseded
Headers show
Series
  • [v3,01/16] powerpc/xive: Remove incorrect debug code
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Commit Message

Benjamin Herrenschmidt Jan. 11, 2018, 4:34 a.m.
This shaves off a bunch of cycles from the KVM exit path
and the XIVE related hypercall.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---
 arch/powerpc/kvm/book3s_hv_builtin.c    |  5 ++---
 arch/powerpc/kvm/book3s_hv_rmhandlers.S | 14 ++++++++------
 2 files changed, 10 insertions(+), 9 deletions(-)

Patch

diff --git a/arch/powerpc/kvm/book3s_hv_builtin.c b/arch/powerpc/kvm/book3s_hv_builtin.c
index 49a2c7825e04..5fbaa8710e0c 100644
--- a/arch/powerpc/kvm/book3s_hv_builtin.c
+++ b/arch/powerpc/kvm/book3s_hv_builtin.c
@@ -209,8 +209,7 @@  long kvmppc_h_random(struct kvm_vcpu *vcpu)
 {
 	int r;
 
-	/* Only need to do the expensive mfmsr() on radix */
-	if (kvm_is_radix(vcpu->kvm) && (mfmsr() & MSR_IR))
+	if (local_paca->kvm_hstate.exit_virt)
 		r = powernv_get_random_long(&vcpu->arch.gpr[4]);
 	else
 		r = powernv_get_random_real_mode(&vcpu->arch.gpr[4]);
@@ -541,7 +540,7 @@  static long kvmppc_read_one_intr(bool *again)
 #ifdef CONFIG_KVM_XICS
 static inline bool is_rm(void)
 {
-	return !(mfmsr() & MSR_DR);
+	return !local_paca->kvm_hstate.exit_virt;
 }
 
 unsigned long kvmppc_rm_h_xirr(struct kvm_vcpu *vcpu)
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index 1e32e188ba17..0024c449340b 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -190,8 +190,8 @@  END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
 	 * we will be in virtual mode at this point, which makes it a
 	 * little easier to get back to the caller.
 	 */
-	mfmsr	r0
-	andi.	r0, r0, MSR_IR		/* in real mode? */
+	lbz	r0,HSTATE_EXIT_VIRT(r13)
+	cmpwi	r0,0
 	bne	.Lvirt_return
 
 	/* RFI into the highmem handler */
@@ -1481,8 +1481,9 @@  guest_exit_cont:		/* r9 = vcpu, r12 = trap, r13 = paca */
 	beq	1f
 	li	r7, TM_SPC_PULL_OS_CTX
 	li	r6, TM_QW1_OS
-	mfmsr	r0
-	andi.	r0, r0, MSR_DR		/* in real mode? */
+	/* Are we in virtual or real mode ? */
+	lbz	r0,HSTATE_EXIT_VIRT(r13)
+	cmpwi	r0,0
 	beq	2f
 	ld	r10, HSTATE_XIVE_TIMA_VIRT(r13)
 	cmpldi	cr0, r10, 0
@@ -2804,8 +2805,9 @@  kvm_cede_exit:
 	stb	r0, VCPU_CEDED(r9)
 1:	/* Enable XIVE escalation */
 	li	r5, XIVE_ESB_SET_PQ_00
-	mfmsr	r0
-	andi.	r0, r0, MSR_DR		/* in real mode? */
+	/* Are we in virtual or real mode ? */
+	lbz	r0,HSTATE_EXIT_VIRT(r13)
+	cmpwi	r0,0
 	beq	1f
 	ld	r10, VCPU_XIVE_ESC_VADDR(r9)
 	cmpdi	r10, 0