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From: Nicholas Piggin <npiggin@gmail.com>
To: kvm-ppc@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org, Nicholas Piggin <npiggin@gmail.com>
Subject: [PATCH v3 32/41] KVM: PPC: Book3S HV P9: Switch to guest MMU context as late as possible
Date: Sat,  6 Mar 2021 01:06:29 +1000	[thread overview]
Message-ID: <20210305150638.2675513-33-npiggin@gmail.com> (raw)
In-Reply-To: <20210305150638.2675513-1-npiggin@gmail.com>

Move MMU context switch as late as reasonably possible to minimise code
running with guest context switched in. This becomes more important when
this code may run in real-mode, with later changes.

Move WARN_ON as early as possible so program check interrupts are less
likely to tangle everything up.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_hv_interrupt.c | 40 +++++++++++++-------------
 1 file changed, 20 insertions(+), 20 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv_interrupt.c b/arch/powerpc/kvm/book3s_hv_interrupt.c
index d81aef6c69d9..48e07cd1b46c 100644
--- a/arch/powerpc/kvm/book3s_hv_interrupt.c
+++ b/arch/powerpc/kvm/book3s_hv_interrupt.c
@@ -143,8 +143,13 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	if (hdec < 0)
 		return BOOK3S_INTERRUPT_HV_DECREMENTER;
 
+	WARN_ON_ONCE(vcpu->arch.shregs.msr & MSR_HV);
+	WARN_ON_ONCE(!(vcpu->arch.shregs.msr & MSR_ME));
+
 	start_timing(vcpu, &vcpu->arch.rm_entry);
 
+	vcpu->arch.ceded = 0;
+
 	if (vc->tb_offset) {
 		u64 new_tb = tb + vc->tb_offset;
 		mtspr(SPRN_TBU40, new_tb);
@@ -193,26 +198,6 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 
 	mtspr(SPRN_HFSCR, vcpu->arch.hfscr);
 
-	mtspr(SPRN_SPRG0, vcpu->arch.shregs.sprg0);
-	mtspr(SPRN_SPRG1, vcpu->arch.shregs.sprg1);
-	mtspr(SPRN_SPRG2, vcpu->arch.shregs.sprg2);
-	mtspr(SPRN_SPRG3, vcpu->arch.shregs.sprg3);
-
-	mtspr(SPRN_AMOR, ~0UL);
-
-	switch_mmu_to_guest_radix(kvm, vcpu, lpcr);
-
-	/*
-	 * P9 suppresses the HDEC exception when LPCR[HDICE] = 0,
-	 * so set guest LPCR (with HDICE) before writing HDEC.
-	 */
-	mtspr(SPRN_HDEC, hdec);
-
-	vcpu->arch.ceded = 0;
-
-	WARN_ON_ONCE(vcpu->arch.shregs.msr & MSR_HV);
-	WARN_ON_ONCE(!(vcpu->arch.shregs.msr & MSR_ME));
-
 	mtspr(SPRN_HSRR0, vcpu->arch.regs.nip);
 	mtspr(SPRN_HSRR1, (vcpu->arch.shregs.msr & ~MSR_HV) | MSR_ME);
 
@@ -231,6 +216,21 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc
 	 */
 	mtspr(SPRN_HDSISR, HDSISR_CANARY);
 
+	mtspr(SPRN_SPRG0, vcpu->arch.shregs.sprg0);
+	mtspr(SPRN_SPRG1, vcpu->arch.shregs.sprg1);
+	mtspr(SPRN_SPRG2, vcpu->arch.shregs.sprg2);
+	mtspr(SPRN_SPRG3, vcpu->arch.shregs.sprg3);
+
+	mtspr(SPRN_AMOR, ~0UL);
+
+	switch_mmu_to_guest_radix(kvm, vcpu, lpcr);
+
+	/*
+	 * P9 suppresses the HDEC exception when LPCR[HDICE] = 0,
+	 * so set guest LPCR (with HDICE) before writing HDEC.
+	 */
+	mtspr(SPRN_HDEC, hdec);
+
 	__mtmsrd(0, 1); /* clear RI */
 
 	mtspr(SPRN_DAR, vcpu->arch.shregs.dar);
-- 
2.23.0


  parent reply	other threads:[~2021-03-05 15:20 UTC|newest]

Thread overview: 79+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-05 15:05 [PATCH v3 00/41] KVM: PPC: Book3S: C-ify the P9 entry/exit code Nicholas Piggin
2021-03-05 15:05 ` [PATCH v3 01/41] KVM: PPC: Book3S HV: Disallow LPCR[AIL] to be set to 1 or 2 Nicholas Piggin
2021-03-08 15:26   ` Fabiano Rosas
2021-03-09  1:11     ` Nicholas Piggin
2021-03-05 15:05 ` [PATCH v3 02/41] KVM: PPC: Book3S HV: Prevent radix guests from setting LPCR[TC] Nicholas Piggin
2021-03-08 15:47   ` Fabiano Rosas
2021-03-09  1:14     ` Nicholas Piggin
2021-03-05 15:06 ` [PATCH v3 03/41] KVM: PPC: Book3S HV: Remove redundant mtspr PSPB Nicholas Piggin
2021-03-12  5:07   ` Daniel Axtens
2021-03-05 15:06 ` [PATCH v3 04/41] KVM: PPC: Book3S HV: remove unused kvmppc_h_protect argument Nicholas Piggin
2021-03-05 15:06 ` [PATCH v3 05/41] KVM: PPC: Book3S HV: Fix CONFIG_SPAPR_TCE_IOMMU=n default hcalls Nicholas Piggin
2021-03-05 15:06 ` [PATCH v3 06/41] powerpc/64s: Remove KVM handler support from CBE_RAS interrupts Nicholas Piggin
2021-03-05 15:06 ` [PATCH v3 07/41] powerpc/64s: remove KVM SKIP test from instruction breakpoint handler Nicholas Piggin
2021-03-05 15:06 ` [PATCH v3 08/41] KVM: PPC: Book3S HV: Ensure MSR[ME] is always set in guest MSR Nicholas Piggin
2021-03-05 15:06 ` [PATCH v3 09/41] KVM: PPC: Book3S 64: move KVM interrupt entry to a common entry point Nicholas Piggin
2021-03-05 15:06 ` [PATCH v3 10/41] KVM: PPC: Book3S 64: Move GUEST_MODE_SKIP test into KVM Nicholas Piggin
2021-03-05 15:06 ` [PATCH v3 11/41] KVM: PPC: Book3S 64: add hcall interrupt handler Nicholas Piggin
2021-03-05 15:06 ` [PATCH v3 12/41] KVM: PPC: Book3S 64: Move hcall early register setup to KVM Nicholas Piggin
2021-03-12  5:45   ` Daniel Axtens
2021-03-16  3:43     ` Nicholas Piggin
2021-03-05 15:06 ` [PATCH v3 13/41] KVM: PPC: Book3S 64: Move interrupt " Nicholas Piggin
2021-03-20  7:19   ` Alexey Kardashevskiy
2021-03-05 15:06 ` [PATCH v3 14/41] KVM: PPC: Book3S 64: move bad_host_intr check to HV handler Nicholas Piggin
2021-03-20  9:07   ` Alexey Kardashevskiy
2021-03-22  3:18     ` Nicholas Piggin
2021-03-05 15:06 ` [PATCH v3 15/41] KVM: PPC: Book3S 64: Minimise hcall handler calling convention differences Nicholas Piggin
2021-03-22  2:09   ` Alexey Kardashevskiy
2021-03-22  4:06   ` Nicholas Piggin
2021-03-05 15:06 ` [PATCH v3 16/41] KVM: PPC: Book3S HV P9: Move radix MMU switching instructions together Nicholas Piggin
2021-03-22  4:24   ` Alexey Kardashevskiy
2021-03-22  5:25     ` Nicholas Piggin
2021-03-22  6:21       ` Alexey Kardashevskiy
2021-03-05 15:06 ` [PATCH v3 17/41] KVM: PPC: Book3S HV P9: implement kvmppc_xive_pull_vcpu in C Nicholas Piggin
2021-03-22  5:05   ` Alexey Kardashevskiy
2021-03-22 16:19   ` Cédric Le Goater
2021-03-22 18:13     ` Nicholas Piggin
2021-03-05 15:06 ` [PATCH v3 18/41] KVM: PPC: Book3S HV P9: Move xive vcpu context management into kvmhv_p9_guest_entry Nicholas Piggin
2021-03-22  5:30   ` Alexey Kardashevskiy
2021-03-05 15:06 ` [PATCH v3 19/41] KVM: PPC: Book3S HV P9: Stop handling hcalls in real-mode in the P9 path Nicholas Piggin
2021-03-17 16:22   ` Fabiano Rosas
2021-03-17 22:41     ` Nicholas Piggin
2021-03-22 16:12     ` Cédric Le Goater
2021-03-22  7:30   ` Alexey Kardashevskiy
2021-03-22 13:15     ` Nicholas Piggin
2021-03-22 16:01       ` Cédric Le Goater
2021-03-22 18:22         ` Nicholas Piggin
2021-03-23  7:26           ` Cédric Le Goater
2021-03-05 15:06 ` [PATCH v3 20/41] KVM: PPC: Book3S HV P9: Move setting HDEC after switching to guest LPCR Nicholas Piggin
2021-03-08 17:52   ` Fabiano Rosas
2021-03-22  8:39   ` Alexey Kardashevskiy
2021-03-22 13:24     ` Nicholas Piggin
2021-03-05 15:06 ` [PATCH v3 21/41] KVM: PPC: Book3S HV P9: Use large decrementer for HDEC Nicholas Piggin
2021-03-22  7:58   ` Alexey Kardashevskiy
2021-03-05 15:06 ` [PATCH v3 22/41] KVM: PPC: Book3S HV P9: Use host timer accounting to avoid decrementer read Nicholas Piggin
2021-03-05 15:06 ` [PATCH v3 23/41] KVM: PPC: Book3S HV P9: Reduce mftb per guest entry/exit Nicholas Piggin
2021-03-12 12:55   ` Fabiano Rosas
2021-03-05 15:06 ` [PATCH v3 24/41] powerpc: add set_dec_or_work API for safely updating decrementer Nicholas Piggin
2021-03-22  9:38   ` Alexey Kardashevskiy
2021-03-05 15:06 ` [PATCH v3 25/41] KVM: PPC: Book3S HV P9: Reduce irq_work vs guest decrementer races Nicholas Piggin
2021-03-23  1:43   ` Alexey Kardashevskiy
2021-03-05 15:06 ` [PATCH v3 26/41] KVM: PPC: Book3S HV P9: Implement the rest of the P9 path in C Nicholas Piggin
2021-03-05 15:06 ` [PATCH v3 27/41] KVM: PPC: Book3S HV P9: inline kvmhv_load_hv_regs_and_go into __kvmhv_vcpu_entry_p9 Nicholas Piggin
2021-03-05 15:06 ` [PATCH v3 28/41] KVM: PPC: Book3S HV P9: Read machine check registers while MSR[RI] is 0 Nicholas Piggin
2021-03-05 15:06 ` [PATCH v3 29/41] KVM: PPC: Book3S HV P9: Improve exit timing accounting coverage Nicholas Piggin
2021-03-05 15:06 ` [PATCH v3 30/41] KVM: PPC: Book3S HV P9: Move SPR loading after expiry time check Nicholas Piggin
2021-03-05 15:06 ` [PATCH v3 31/41] KVM: PPC: Book3S HV P9: Add helpers for OS SPR handling Nicholas Piggin
2021-03-05 15:06 ` Nicholas Piggin [this message]
2021-03-05 15:06 ` [PATCH v3 33/41] KVM: PPC: Book3S HV: Implement radix prefetch workaround by disabling MMU Nicholas Piggin
2021-03-05 15:06 ` [PATCH v3 34/41] KVM: PPC: Book3S HV: Remove support for dependent threads mode on P9 Nicholas Piggin
2021-03-17 15:11   ` Aneesh Kumar K.V
2021-03-22  3:27     ` Nicholas Piggin
2021-03-05 15:06 ` [PATCH v3 35/41] KVM: PPC: Book3S HV: Remove radix guest support from P7/8 path Nicholas Piggin
2021-03-05 15:06 ` [PATCH v3 36/41] KVM: PPC: Book3S HV P9: Allow all P9 processors to enable nested HV Nicholas Piggin
2021-03-05 15:06 ` [PATCH v3 37/41] KVM: PPC: Book3S HV: small pseries_do_hcall cleanup Nicholas Piggin
2021-03-05 15:06 ` [PATCH v3 38/41] KVM: PPC: Book3S HV: add virtual mode handlers for HPT hcalls and page faults Nicholas Piggin
2021-03-05 15:06 ` [PATCH v3 39/41] KVM: PPC: Book3S HV P9: implement hash guest support Nicholas Piggin
2021-03-05 15:06 ` [PATCH v3 40/41] KVM: PPC: Book3S HV P9: implement hash host / " Nicholas Piggin
2021-03-05 15:06 ` [PATCH v3 41/41] KVM: PPC: Book3S HV: remove ISA v3.0 and v3.1 support from P7/8 path Nicholas Piggin
2021-03-16  6:06 ` [PATCH v3 00/41] KVM: PPC: Book3S: C-ify the P9 entry/exit code Nicholas Piggin

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