From 92a5199b29f6519aa5f774f4b96dc41954f641d1 Mon Sep 17 00:00:00 2001 From: Tom Lendacky Date: Tue, 26 Jan 2021 11:36:47 -0600 Subject: sev/i386: Don't allow a system reset under an SEV-ES guest An SEV-ES guest does not allow register state to be altered once it has been measured. When an SEV-ES guest issues a reboot command, Qemu will reset the vCPU state and resume the guest. This will cause failures under SEV-ES. Prevent that from occuring by introducing an arch-specific callback that returns a boolean indicating whether vCPUs are resettable. Cc: Peter Maydell Cc: Aurelien Jarno Cc: Jiaxun Yang Cc: Aleksandar Rikalo Cc: David Gibson Cc: David Hildenbrand Reviewed-by: Dr. David Alan Gilbert Signed-off-by: Tom Lendacky Reviewed-by: Venu Busireddy Message-Id: <1ac39c441b9a3e970e9556e1cc29d0a0814de6fd.1611682609.git.thomas.lendacky@amd.com> Signed-off-by: Paolo Bonzini --- include/sysemu/cpus.h | 2 ++ include/sysemu/hw_accel.h | 5 +++++ include/sysemu/kvm.h | 10 ++++++++++ 3 files changed, 17 insertions(+) (limited to 'include') diff --git a/include/sysemu/cpus.h b/include/sysemu/cpus.h index 2cd74392e0..868f1192de 100644 --- a/include/sysemu/cpus.h +++ b/include/sysemu/cpus.h @@ -41,6 +41,8 @@ extern int icount_align_option; /* Unblock cpu */ void qemu_cpu_kick_self(void); +bool cpus_are_resettable(void); + void cpu_synchronize_all_states(void); void cpu_synchronize_all_post_reset(void); void cpu_synchronize_all_post_init(void); diff --git a/include/sysemu/hw_accel.h b/include/sysemu/hw_accel.h index ffed6192a3..61672f9b32 100644 --- a/include/sysemu/hw_accel.h +++ b/include/sysemu/hw_accel.h @@ -22,4 +22,9 @@ void cpu_synchronize_post_reset(CPUState *cpu); void cpu_synchronize_post_init(CPUState *cpu); void cpu_synchronize_pre_loadvm(CPUState *cpu); +static inline bool cpu_check_are_resettable(void) +{ + return kvm_enabled() ? kvm_cpu_check_are_resettable() : true; +} + #endif /* QEMU_HW_ACCEL_H */ diff --git a/include/sysemu/kvm.h b/include/sysemu/kvm.h index c5546bdecc..687c598be9 100644 --- a/include/sysemu/kvm.h +++ b/include/sysemu/kvm.h @@ -541,4 +541,14 @@ int kvm_get_max_memslots(void); /* Notify resamplefd for EOI of specific interrupts. */ void kvm_resample_fd_notify(int gsi); +/** + * kvm_cpu_check_are_resettable - return whether CPUs can be reset + * + * Returns: true: CPUs are resettable + * false: CPUs are not resettable + */ +bool kvm_cpu_check_are_resettable(void); + +bool kvm_arch_cpu_check_are_resettable(void); + #endif -- cgit v1.2.3-55-g7522