[PATCH 24/26] KVM: PPC: Book3S PR: add guard code to prevent returning to guest with PR=0 and Transactional state
From: <hidden>
Date: 2018-01-11 10:13:18
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> Currently PR KVM doesn't support transaction memory at guest privilege state. This patch adds a check at setting guest msr, so that we can never return to guest with PR=0 and TS=0b10. A tabort will be emulated to indicate this and fail transaction immediately. Signed-off-by: Simon Guo <redacted> --- arch/powerpc/include/uapi/asm/tm.h | 2 +- arch/powerpc/kvm/book3s.h | 1 + arch/powerpc/kvm/book3s_emulate.c | 2 +- arch/powerpc/kvm/book3s_pr.c | 13 ++++++++++++- 4 files changed, 15 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/include/uapi/asm/tm.h b/arch/powerpc/include/uapi/asm/tm.h
index e1bf0e2..e2947c9 100644
--- a/arch/powerpc/include/uapi/asm/tm.h
+++ b/arch/powerpc/include/uapi/asm/tm.h@@ -13,7 +13,7 @@ #define TM_CAUSE_TLBI 0xdc #define TM_CAUSE_FAC_UNAV 0xda #define TM_CAUSE_SYSCALL 0xd8 -#define TM_CAUSE_MISC 0xd6 /* future use */ +#define TM_CAUSE_PRIV_T 0xd6 #define TM_CAUSE_SIGNAL 0xd4 #define TM_CAUSE_ALIGNMENT 0xd2 #define TM_CAUSE_EMULATE 0xd0
diff --git a/arch/powerpc/kvm/book3s.h b/arch/powerpc/kvm/book3s.h
index d2b3ec0..9beb57b 100644
--- a/arch/powerpc/kvm/book3s.h
+++ b/arch/powerpc/kvm/book3s.h@@ -32,4 +32,5 @@ extern int kvmppc_core_emulate_mfspr_pr(struct kvm_vcpu *vcpu, extern int kvmppc_book3s_init_pr(void); extern void kvmppc_book3s_exit_pr(void); +extern void kvmppc_emulate_tabort(struct kvm_vcpu *vcpu, int ra_val); #endif
diff --git a/arch/powerpc/kvm/book3s_emulate.c b/arch/powerpc/kvm/book3s_emulate.c
index 65eb236..11d76be 100644
--- a/arch/powerpc/kvm/book3s_emulate.c
+++ b/arch/powerpc/kvm/book3s_emulate.c@@ -196,7 +196,7 @@ static void kvmppc_emulate_trchkpt(struct kvm_vcpu *vcpu) } /* emulate tabort. at guest privilege state */ -static void kvmppc_emulate_tabort(struct kvm_vcpu *vcpu, int ra_val) +void kvmppc_emulate_tabort(struct kvm_vcpu *vcpu, int ra_val) { /* currently we only emulate tabort. but no emulation of other * tabort variants since there is no kernel usage of them at
diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c
index f65415b..cc568bc 100644
--- a/arch/powerpc/kvm/book3s_pr.c
+++ b/arch/powerpc/kvm/book3s_pr.c@@ -461,12 +461,23 @@ static void kvmppc_recalc_shadow_msr(struct kvm_vcpu *vcpu) static void kvmppc_set_msr_pr(struct kvm_vcpu *vcpu, u64 msr) { - ulong old_msr = kvmppc_get_msr(vcpu); + ulong old_msr; #ifdef EXIT_DEBUG printk(KERN_INFO "KVM: Set MSR to 0x%llx\n", msr); #endif +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM + /* We should never target guest MSR to TS=10 && PR=0, + * since we always fail transaction for guest privilege + * state. + */ + if (!(msr & MSR_PR) && MSR_TM_TRANSACTIONAL(msr)) + kvmppc_emulate_tabort(vcpu, + TM_CAUSE_PRIV_T | TM_CAUSE_PERSISTENT); +#endif + + old_msr = kvmppc_get_msr(vcpu); msr &= to_book3s(vcpu)->msr_mask; kvmppc_set_msr_fast(vcpu, msr); kvmppc_recalc_shadow_msr(vcpu);
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1.8.3.1