On 4/2/2024 5:42 PM, Michael Roth wrote:
On Tue, Apr 02, 2024 at 05:31:09PM -0500, Kalra, Ashish wrote:On 4/2/2024 5:09 PM, Tom Lendacky wrote:On 3/12/24 13:47, Ashish Kalra wrote:From: Ashish Kalra <ashish.kalra@xxxxxxx> RMP table start and end physical range may not be aligned to 2MB in the e820 tables causing fatal RMP page faults during kexec boot when new page allocations are done in the same 2MB page as the RMP table. Check if RMP table start and end physical range in e820_table is not aligned to 2MB and in that case use e820__range_update() to map this range to reserved. Override e820__memory_setup_default() to check and apply these RMP table fixups in e820_table before e820_table is used to setup e280_table_firmware and e820_table_kexec. Fixes: c3b86e61b756 ("x86/cpufeatures: Enable/unmask SEV-SNP CPU feature") Signed-off-by: Ashish Kalra <ashish.kalra@xxxxxxx> --- arch/x86/virt/svm/sev.c | 52 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 52 insertions(+) diff --git a/arch/x86/virt/svm/sev.c b/arch/x86/virt/svm/sev.c index cffe1157a90a..e0d7584df28f 100644 --- a/arch/x86/virt/svm/sev.c +++ b/arch/x86/virt/svm/sev.c @@ -65,6 +65,8 @@ static u64 probed_rmp_base, probed_rmp_size; static struct rmpentry *rmptable __ro_after_init; static u64 rmptable_max_pfn __ro_after_init; +static char *__init snp_rmptable_e820_fixup(void); + static LIST_HEAD(snp_leaked_pages_list); static DEFINE_SPINLOCK(snp_leaked_pages_list_lock); @@ -160,9 +162,59 @@ bool snp_probe_rmptable_info(void) pr_info("RMP table physical range [0x%016llx - 0x%016llx]\n", probed_rmp_base, probed_rmp_base + probed_rmp_size - 1); + /* + * Override e820__memory_setup_default() to do any RMP table fixups + * for kexec if required. + */ + x86_init.resources.memory_setup = snp_rmptable_e820_fixup;This produces a build warning: WARNING: modpost: vmlinux: section mismatch in reference: snp_probe_rmptable_info+0x95 (section: .text) -> x86_init (section: .init.data) WARNING: modpost: vmlinux: section mismatch in reference: snp_probe_rmptable_info+0x99 (section: .text) -> snp_rmptable_e820_fixup (section: .init.text)Oh, so this requires snp_probe_rmptable_info() to be fixed to use the __init macro. I believe that snp_probe_rmptable_info() should be anyway using the __init macro and this fix for snp_probe_rmptable_info() needs to be sent as a separate patch and regardless of this patch getting merged or not.I think you'll hit issues with: bsp_determine_snp() -> //non-__init snp_probe_rmptable_info() //__init and bsp_determine_snp() sticks around as a function pointer assigned to cpuinfo_x86 so I don't think you can use __init there. So might need to just drop __init from snp_rmptable_e820_fixup().
Actually, that will not help as snp_probe_rmptable_info() is *also* accessing x86_init.resources.memory_setup
Thanks, Ashish
Thanks, AshishThanks, Tom+ return true; }
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