Kernel KVM-PPC virtualization development
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From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Paul Mackerras <paulus@ozlabs.org>
Cc: kvm@vger.kernel.org, kvm-ppc@vger.kernel.org,
	Benjamin Herrenschmidt <benh@kernel.crashing.org>
Subject: [PATCH v2 11/11] powerpc/kvm: Use the PACA virt/real mode info instead of mfmsr
Date: Thu, 23 Nov 2017 04:36:19 +0000	[thread overview]
Message-ID: <20171123043619.15301-11-benh@kernel.crashing.org> (raw)
In-Reply-To: <20171123043619.15301-1-benh@kernel.crashing.org>

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 | 16 ++++++++++------
 2 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv_builtin.c b/arch/powerpc/kvm/book3s_hv_builtin.c
index 90644db9d38e..45525b76b724 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]);
@@ -524,7 +523,7 @@ 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 83862fba8cfb..ade13f7a9077 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -81,6 +81,8 @@ _GLOBAL_TOC(kvmppc_hv_entry_trampoline)
 	RFI
 
 kvmppc_call_hv_entry:
+	li	r0,0
+	stb	r0,HSTATE_EXIT_VIRT(r13)
 	ld	r4, HSTATE_KVM_VCPU(r13)
 	bl	kvmppc_hv_entry
 
@@ -176,8 +178,8 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_300)
 	 * 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 */
@@ -1440,8 +1442,9 @@ 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
@@ -2749,8 +2752,9 @@ 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
-- 
2.14.3


  parent reply	other threads:[~2017-11-23  4:36 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-11-23  4:36 [PATCH v2 01/11] powerpc/kvm/xive: Add more debugfs queues info Benjamin Herrenschmidt
2017-11-23  4:36 ` [PATCH v2 02/11] powerpc/kvm/xive: Enable use of the new "single escalation" feature Benjamin Herrenschmidt
2017-11-23  4:36 ` [PATCH v2 03/11] powerpc/kvm/xive: Don't use existing "prodded" flag for xive escalations Benjamin Herrenschmidt
2017-11-23  4:36 ` [PATCH v2 04/11] powerpc/kvm/xive: Check DR not IR to chose real vs virt mode MMIOs Benjamin Herrenschmidt
2017-11-23  4:36 ` [PATCH v2 05/11] powerpc/kvm/xive: Make xive_pushed a byte, not a word Benjamin Herrenschmidt
2017-11-23  4:36 ` [PATCH v2 06/11] powerpc/xive: Move definition of ESB bits Benjamin Herrenschmidt
2017-11-23  4:36 ` [PATCH v2 07/11] powerpc/xive: Add interrupt flag to disable automatic EOI Benjamin Herrenschmidt
2017-11-23  4:36 ` [PATCH v2 08/11] powerpc/kvm/xive: Keep escalation interrupt masked unless ceded Benjamin Herrenschmidt
2017-11-25  4:56   ` Paul Mackerras
2017-11-26 21:55     ` Benjamin Herrenschmidt
2017-11-23  4:36 ` [PATCH v2 09/11] powerpc/kvm: Make "no_xive:" label local Benjamin Herrenschmidt
2017-11-23  4:36 ` [PATCH v2 10/11] powerpc/kvm: Store the MMU mode in the PACA on KVM exit Benjamin Herrenschmidt
2017-11-24 15:15   ` kbuild test robot
2017-11-25  5:03   ` Paul Mackerras
2017-11-26 21:57     ` Benjamin Herrenschmidt
2017-11-23  4:36 ` Benjamin Herrenschmidt [this message]
2017-11-25  5:17   ` [PATCH v2 11/11] powerpc/kvm: Use the PACA virt/real mode info instead of mfmsr Paul Mackerras
2017-11-26 21:58     ` Benjamin Herrenschmidt

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