From af22b193436b997cdd9ab84852059b9194dc5658 Mon Sep 17 00:00:00 2001 From: Andrew Scull Date: Fri, 19 Feb 2021 12:24:06 +0000 Subject: [PATCH] FROMGIT: KVM: arm64: Fix nVHE hyp panic host context restore When panicking from the nVHE hyp and restoring the host context, x29 is expected to hold a pointer to the host context. This wasn't being done so fix it to make sure there's a valid pointer the host context being used. Rather than passing a boolean indicating whether or not the host context should be restored, instead pass the pointer to the host context. NULL is passed to indicate that no context should be restored. Fixes: a2e102e20fd6 ("KVM: arm64: nVHE: Handle hyp panics") Cc: stable@vger.kernel.org Signed-off-by: Andrew Scull [maz: partial rewrite to fit 5.12-rc1] Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20210219122406.1337626-1-ascull@google.com (cherry picked from commit 5c4dfcdc4c23cc0d043b005df7f73cc953a6c627 git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm.git fixes) Signed-off-by: Will Deacon Bug: 178098380 Test: atest VirtualizationHostTestCases on an EL2-enabled device Change-Id: Ia94e0d431a07cf5f37d2aa0e47037effc382a3fd --- arch/arm64/include/asm/kvm_hyp.h | 3 ++- arch/arm64/kvm/hyp/nvhe/host.S | 15 ++++++++------- arch/arm64/kvm/hyp/nvhe/switch.c | 3 +-- 3 files changed, 11 insertions(+), 10 deletions(-) diff --git a/arch/arm64/include/asm/kvm_hyp.h b/arch/arm64/include/asm/kvm_hyp.h index 385bd7dd3d39..32ae676236b6 100644 --- a/arch/arm64/include/asm/kvm_hyp.h +++ b/arch/arm64/include/asm/kvm_hyp.h @@ -102,7 +102,8 @@ bool kvm_host_psci_handler(struct kvm_cpu_context *host_ctxt); void __noreturn hyp_panic(void); #ifdef __KVM_NVHE_HYPERVISOR__ -void __noreturn __hyp_do_panic(bool restore_host, u64 spsr, u64 elr, u64 par); +void __noreturn __hyp_do_panic(struct kvm_cpu_context *host_ctxt, u64 spsr, + u64 elr, u64 par); #endif #endif /* __ARM64_KVM_HYP_H__ */ diff --git a/arch/arm64/kvm/hyp/nvhe/host.S b/arch/arm64/kvm/hyp/nvhe/host.S index 6585a7cbbc56..5d94584840cc 100644 --- a/arch/arm64/kvm/hyp/nvhe/host.S +++ b/arch/arm64/kvm/hyp/nvhe/host.S @@ -71,7 +71,8 @@ SYM_FUNC_START(__host_enter) SYM_FUNC_END(__host_enter) /* - * void __noreturn __hyp_do_panic(bool restore_host, u64 spsr, u64 elr, u64 par); + * void __noreturn __hyp_do_panic(struct kvm_cpu_context *host_ctxt, u64 spsr, + * u64 elr, u64 par); */ SYM_FUNC_START(__hyp_do_panic) /* Prepare and exit to the host's panic funciton. */ @@ -82,9 +83,11 @@ SYM_FUNC_START(__hyp_do_panic) hyp_kimg_va lr, x6 msr elr_el2, lr - /* Set the panic format string. Use the, now free, LR as scratch. */ - ldr lr, =__hyp_panic_string - hyp_kimg_va lr, x6 + mov x29, x0 + + /* Load the format string into x0 and arguments into x1-7 */ + ldr x0, =__hyp_panic_string + hyp_kimg_va x0, x6 /* Load the format arguments into x1-7. */ mov x6, x3 @@ -94,9 +97,7 @@ SYM_FUNC_START(__hyp_do_panic) mrs x5, hpfar_el2 /* Enter the host, conditionally restoring the host context. */ - cmp x0, xzr - mov x0, lr - b.eq __host_enter_without_restoring + cbz x29, __host_enter_without_restoring b __host_enter_for_panic SYM_FUNC_END(__hyp_do_panic) diff --git a/arch/arm64/kvm/hyp/nvhe/switch.c b/arch/arm64/kvm/hyp/nvhe/switch.c index d6ea5c8b5551..84d2a7012f74 100644 --- a/arch/arm64/kvm/hyp/nvhe/switch.c +++ b/arch/arm64/kvm/hyp/nvhe/switch.c @@ -268,7 +268,6 @@ void __noreturn hyp_panic(void) u64 spsr = read_sysreg_el2(SYS_SPSR); u64 elr = read_sysreg_el2(SYS_ELR); u64 par = read_sysreg_par(); - bool restore_host = true; struct kvm_cpu_context *host_ctxt; struct kvm_vcpu *vcpu; @@ -282,7 +281,7 @@ void __noreturn hyp_panic(void) __sysreg_restore_state_nvhe(host_ctxt); } - __hyp_do_panic(restore_host, spsr, elr, par); + __hyp_do_panic(host_ctxt, spsr, elr, par); unreachable(); }