Commit: 368a540e0232 (x86/kvmclock: Remove memblock dependency) caused SEV guest regression. When SEV is active, we map the shared variables (wall_clock and hv_clock_boot) with C=0 to ensure that both the guest and the hypervisor are able to access the data. To map the variables we use kernel_physical_mapping_init() to split the large pages, but splitting large pages requires allocating a new PMD, which fails now that kvmclock initialization is called early during boot.
Recently we added a special .data..decrypted section to hold the shared variables. This section is mapped with C=0 early during boot. Use __decrypted attribute to put the wall_clock and hv_clock_boot in .data..decrypted section so that they are mapped with C=0. Signed-off-by: Brijesh Singh <[email protected]> Reviewed-by: Tom Lendacky <[email protected]> Fixes: 368a540e0232 ("x86/kvmclock: Remove memblock dependency") Cc: Tom Lendacky <[email protected]> Cc: [email protected] Cc: Thomas Gleixner <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: "H. Peter Anvin" <[email protected]> Cc: [email protected] Cc: Paolo Bonzini <[email protected]> Cc: Sean Christopherson <[email protected]> Cc: [email protected] Cc: "Radim Krčmář" <[email protected]> --- arch/x86/kernel/kvmclock.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c index 1e67646..376fd3a 100644 --- a/arch/x86/kernel/kvmclock.c +++ b/arch/x86/kernel/kvmclock.c @@ -61,8 +61,8 @@ early_param("no-kvmclock-vsyscall", parse_no_kvmclock_vsyscall); (PAGE_SIZE / sizeof(struct pvclock_vsyscall_time_info)) static struct pvclock_vsyscall_time_info - hv_clock_boot[HVC_BOOT_ARRAY_SIZE] __aligned(PAGE_SIZE); -static struct pvclock_wall_clock wall_clock; + hv_clock_boot[HVC_BOOT_ARRAY_SIZE] __decrypted __aligned(PAGE_SIZE); +static struct pvclock_wall_clock wall_clock __decrypted; static DEFINE_PER_CPU(struct pvclock_vsyscall_time_info *, hv_clock_per_cpu); static inline struct pvclock_vcpu_time_info *this_cpu_pvti(void) -- 2.7.4
