Commit 68ab07b9 authored by Simon Guo's avatar Simon Guo Committed by Paul Mackerras
Browse files

KVM: PPC: Book3S PR: Add guard code to prevent returning to guest with PR=0 and Transactional state 



Currently PR KVM doesn't support transaction memory in guest privileged
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.

[paulus@ozlabs.org - don't change the TM_CAUSE_MISC definition, instead
 use TM_CAUSE_KVM_FAC_UNAV.]

Signed-off-by: default avatarSimon Guo <wei.guo.simon@gmail.com>
Signed-off-by: default avatarPaul Mackerras <paulus@ozlabs.org>
parent 26798f88

arch/powerpc/kvm/book3s.h

+6 −0
Original line number Diff line number Diff line
@@ -31,4 +31,10 @@ 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);



#ifdef CONFIG_PPC_TRANSACTIONAL_MEM

extern void kvmppc_emulate_tabort(struct kvm_vcpu *vcpu, int ra_val);

#else

static inline void kvmppc_emulate_tabort(struct kvm_vcpu *vcpu, int ra_val) {}

#endif



#endif

arch/powerpc/kvm/book3s_emulate.c

+1 −1
Original line number Diff line number Diff line
@@ -199,7 +199,7 @@ 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

arch/powerpc/kvm/book3s_pr.c

+12 −1
Original line number Diff line number Diff line
@@ -446,12 +446,23 @@ static void kvm_set_spte_hva_pr(struct kvm *kvm, unsigned long hva, pte_t pte) 


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_KVM_FAC_UNAV | 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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