[PATCH v2 15/30] KVM: PPC: Book3S PR: add transaction memory save/restore skeleton for PR KVM
From: <hidden>
Date: 2018-02-27 18:01:18
Also in:
kvm
Subsystem:
kernel virtual machine for powerpc (kvm/powerpc), linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Linus Torvalds
From: Simon Guo <redacted>
The transaction memory checkpoint area save/restore behavior is
triggered when VCPU qemu process is switching out/into CPU. ie.
at kvmppc_core_vcpu_put_pr() and kvmppc_core_vcpu_load_pr().
MSR TM active state is determined by TS bits:
active: 10(transactional) or 01 (suspended)
inactive: 00 (non-transactional)
We don't "fake" TM functionality for guest. We "sync" guest virtual
MSR TM active state(10 or 01) with shadow MSR. That is to say,
we don't emulate a transactional guest with a TM inactive MSR.
TM SPR support(TFIAR/TFAR/TEXASR) has already been supported by
commit 9916d57e64a4 ("KVM: PPC: Book3S PR: Expose TM registers").
Math register support (FPR/VMX/VSX) will be done at subsequent
patch.
Whether TM context need to be saved/restored can be determined
by kvmppc_get_msr() TM active state:
* TM active - save/restore TM context
* TM inactive - no need to do so and only save/restore
TM SPRs.
Signed-off-by: Simon Guo <redacted>
Suggested-by: Paul Mackerras <redacted>
---
arch/powerpc/include/asm/kvm_book3s.h | 9 +++++++++
arch/powerpc/include/asm/kvm_host.h | 1 -
arch/powerpc/kvm/book3s_pr.c | 27 +++++++++++++++++++++++++++
3 files changed, 36 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/include/asm/kvm_book3s.h b/arch/powerpc/include/asm/kvm_book3s.h
index 9a66700..5911c3b 100644
--- a/arch/powerpc/include/asm/kvm_book3s.h
+++ b/arch/powerpc/include/asm/kvm_book3s.h@@ -253,6 +253,15 @@ extern void kvmppc_copy_to_svcpu(struct kvmppc_book3s_shadow_vcpu *svcpu, struct kvm_vcpu *vcpu); extern void kvmppc_copy_from_svcpu(struct kvm_vcpu *vcpu, struct kvmppc_book3s_shadow_vcpu *svcpu); + +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM +void kvmppc_save_tm_pr(struct kvm_vcpu *vcpu); +void kvmppc_restore_tm_pr(struct kvm_vcpu *vcpu); +#else +static inline void kvmppc_save_tm_pr(struct kvm_vcpu *vcpu) {} +static inline void kvmppc_restore_tm_pr(struct kvm_vcpu *vcpu) {} +#endif + extern int kvm_irq_bypass; static inline struct kvmppc_vcpu_book3s *to_book3s(struct kvm_vcpu *vcpu)
diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index fef8133..89b3fed 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h@@ -626,7 +626,6 @@ struct kvm_vcpu_arch { struct thread_vr_state vr_tm; u32 vrsave_tm; /* also USPRG0 */ - #endif #ifdef CONFIG_KVM_EXIT_TIMING
diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c
index 91d0e59..ac9d58f 100644
--- a/arch/powerpc/kvm/book3s_pr.c
+++ b/arch/powerpc/kvm/book3s_pr.c@@ -43,6 +43,7 @@ #include <linux/module.h> #include <linux/miscdevice.h> #include <asm/asm-prototypes.h> +#include <asm/tm.h> #include "book3s.h"
@@ -115,6 +116,8 @@ static void kvmppc_core_vcpu_load_pr(struct kvm_vcpu *vcpu, int cpu) if (kvmppc_is_split_real(vcpu)) kvmppc_fixup_split_real(vcpu); + + kvmppc_restore_tm_pr(vcpu); } static void kvmppc_core_vcpu_put_pr(struct kvm_vcpu *vcpu)
@@ -134,6 +137,7 @@ static void kvmppc_core_vcpu_put_pr(struct kvm_vcpu *vcpu) kvmppc_giveup_ext(vcpu, MSR_FP | MSR_VEC | MSR_VSX); kvmppc_giveup_fac(vcpu, FSCR_TAR_LG); + kvmppc_save_tm_pr(vcpu); /* Enable AIL if supported */ if (cpu_has_feature(CPU_FTR_HVMODE) &&
@@ -306,6 +310,29 @@ static inline void kvmppc_restore_tm_sprs(struct kvm_vcpu *vcpu) tm_disable(); } +void kvmppc_save_tm_pr(struct kvm_vcpu *vcpu) +{ + if (!(MSR_TM_ACTIVE(kvmppc_get_msr(vcpu)))) { + kvmppc_save_tm_sprs(vcpu); + return; + } + + preempt_disable(); + _kvmppc_save_tm_pr(vcpu, mfmsr()); + preempt_enable(); +} + +void kvmppc_restore_tm_pr(struct kvm_vcpu *vcpu) +{ + if (!MSR_TM_ACTIVE(kvmppc_get_msr(vcpu))) { + kvmppc_restore_tm_sprs(vcpu); + return; + } + + preempt_disable(); + _kvmppc_restore_tm_pr(vcpu, kvmppc_get_msr(vcpu)); + preempt_enable(); +} #endif static int kvmppc_core_check_requests_pr(struct kvm_vcpu *vcpu)
--
1.8.3.1