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 21/41] KVM: PPC: Book3S HV P9: Use large decrementer for HDEC
Date: Sat, 6 Mar 2021 01:06:18 +1000 [thread overview]
Message-ID: <20210305150638.2675513-22-npiggin@gmail.com> (raw)
In-Reply-To: <20210305150638.2675513-1-npiggin@gmail.com>
On processors that don't suppress the HDEC exceptions when LPCR[HDICE]=0,
this could help reduce needless guest exits due to leftover exceptions on
entering the guest.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/include/asm/time.h | 2 ++
arch/powerpc/kvm/book3s_hv.c | 3 ++-
2 files changed, 4 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/include/asm/time.h b/arch/powerpc/include/asm/time.h
index 8dd3cdb25338..68d94711811e 100644
--- a/arch/powerpc/include/asm/time.h
+++ b/arch/powerpc/include/asm/time.h
@@ -18,6 +18,8 @@
#include <asm/vdso/timebase.h>
/* time.c */
+extern u64 decrementer_max;
+
extern unsigned long tb_ticks_per_jiffy;
extern unsigned long tb_ticks_per_usec;
extern unsigned long tb_ticks_per_sec;
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index ffde1917ab68..24b0680f0ad7 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3623,7 +3623,8 @@ static int kvmhv_load_hv_regs_and_go(struct kvm_vcpu *vcpu, u64 time_limit,
vc->tb_offset_applied = 0;
}
- mtspr(SPRN_HDEC, 0x7fffffff);
+ /* HDEC must be at least as large as DEC, so decrementer_max fits */
+ mtspr(SPRN_HDEC, decrementer_max);
switch_mmu_to_host_radix(kvm, host_pidr);
--
2.23.0
next prev parent reply other threads:[~2021-03-05 15:16 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 ` Nicholas Piggin [this message]
2021-03-22 7:58 ` [PATCH v3 21/41] KVM: PPC: Book3S HV P9: Use large decrementer for HDEC 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 ` [PATCH v3 32/41] KVM: PPC: Book3S HV P9: Switch to guest MMU context as late as possible Nicholas Piggin
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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