From: Nicholas Piggin <npiggin@gmail•com>
To: linuxppc-dev@lists•ozlabs.org
Cc: Nicholas Piggin <npiggin@gmail•com>
Subject: [PATCH] KVM: PPC: Book3S HV Nested: Fix nested HFSCR being clobbered with multiple vCPUs
Date: Sat, 22 Jan 2022 20:55:30 +1000 [thread overview]
Message-ID: <20220122105530.3477250-1-npiggin@gmail.com> (raw)
The L0 is storing HFSCR requested by the L1 for the L2 in struct
kvm_nested_guest when the L1 requests a vCPU enter L2. kvm_nested_guest
is not a per-vCPU structure. Hilarity ensues.
Fix it by moving the nested hfscr into the vCPU structure together with
the other per-vCPU nested fields.
Fixes: 8b210a880b35 ("KVM: PPC: Book3S HV Nested: Make nested HFSCR state accessible")
Signed-off-by: Nicholas Piggin <npiggin@gmail•com>
---
arch/powerpc/include/asm/kvm_book3s_64.h | 1 -
arch/powerpc/include/asm/kvm_host.h | 1 +
arch/powerpc/kvm/book3s_hv.c | 3 +--
arch/powerpc/kvm/book3s_hv_nested.c | 2 +-
4 files changed, 3 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/include/asm/kvm_book3s_64.h b/arch/powerpc/include/asm/kvm_book3s_64.h
index fe07558173ef..827038a33064 100644
--- a/arch/powerpc/include/asm/kvm_book3s_64.h
+++ b/arch/powerpc/include/asm/kvm_book3s_64.h
@@ -39,7 +39,6 @@ struct kvm_nested_guest {
pgd_t *shadow_pgtable; /* our page table for this guest */
u64 l1_gr_to_hr; /* L1's addr of part'n-scoped table */
u64 process_table; /* process table entry for this guest */
- u64 hfscr; /* HFSCR that the L1 requested for this nested guest */
long refcnt; /* number of pointers to this struct */
struct mutex tlb_lock; /* serialize page faults and tlbies */
struct kvm_nested_guest *next;
diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index a770443cd6e0..d9bf60bf0816 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -818,6 +818,7 @@ struct kvm_vcpu_arch {
/* For support of nested guests */
struct kvm_nested_guest *nested;
+ u64 nested_hfscr; /* HFSCR that the L1 requested for the nested guest */
u32 nested_vcpu_id;
gpa_t nested_io_gpr;
#endif
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index d1817cd9a691..84c89f08ae9a 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -1816,7 +1816,6 @@ static int kvmppc_handle_exit_hv(struct kvm_vcpu *vcpu,
static int kvmppc_handle_nested_exit(struct kvm_vcpu *vcpu)
{
- struct kvm_nested_guest *nested = vcpu->arch.nested;
int r;
int srcu_idx;
@@ -1922,7 +1921,7 @@ static int kvmppc_handle_nested_exit(struct kvm_vcpu *vcpu)
* it into a HEAI.
*/
if (!(vcpu->arch.hfscr_permitted & (1UL << cause)) ||
- (nested->hfscr & (1UL << cause))) {
+ (vcpu->arch.nested_hfscr & (1UL << cause))) {
vcpu->arch.trap = BOOK3S_INTERRUPT_H_EMUL_ASSIST;
/*
diff --git a/arch/powerpc/kvm/book3s_hv_nested.c b/arch/powerpc/kvm/book3s_hv_nested.c
index 8f8daaeeb3b7..9d373f8963ee 100644
--- a/arch/powerpc/kvm/book3s_hv_nested.c
+++ b/arch/powerpc/kvm/book3s_hv_nested.c
@@ -363,7 +363,7 @@ long kvmhv_enter_nested_guest(struct kvm_vcpu *vcpu)
/* set L1 state to L2 state */
vcpu->arch.nested = l2;
vcpu->arch.nested_vcpu_id = l2_hv.vcpu_token;
- l2->hfscr = l2_hv.hfscr;
+ vcpu->arch.nested_hfscr = l2_hv.hfscr;
vcpu->arch.regs = l2_regs;
/* Guest must always run with ME enabled, HV disabled. */
--
2.23.0
next reply other threads:[~2022-01-22 10:56 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-22 10:55 Nicholas Piggin [this message]
2022-01-24 17:17 ` [PATCH] KVM: PPC: Book3S HV Nested: Fix nested HFSCR being clobbered with multiple vCPUs Fabiano Rosas
2022-01-29 11:14 ` Michael Ellerman
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